Transcript for:
VCP 34 Lecture Notes on Energy Systems

[Music] hey guys Welcome to our vcp 34 revision lecture my name is Angelica and I'm going to be your lecturer or cheater today so just a little bit about AI notes background we found in 2007 as a means to kind of even out the VC playing field we used to give big inperson lectures but after Co we've switched to an online format which is a lot more convenient for everyone I think so yeah this isn't live right now but I'm looking forward to hearing from you if you've got any questions just pop them in the chat and I'll get back to soon as I can so just a little bit more about AAR notes I love it I used it all throughout high school and I'm not even just saying that because I literally am doing this lecture I would actually use this all the time in high school especially for Bio in particular I was super active in the forums and I was always posting qu questions in the discussion space um I think the really useful thing about that is that you've got lots of students who who scored really highly throughout VC who would just jump on and reply as soon as they can and I remember particularly around exam season or exam time I'd be getting responses within like like a minute of posting on the forums like I'm not even joking it was super fast so I really appreciated the forums that was what I spent the most time on but I also actually went to these lectures when I was in high school so I used to always go to the bio ones every year um so you're 11 and you're 12 and I found them super helpful and they kind of like helped me do well in school highly in VC so I really appreciate that also AP from that we've got really great study notes written by me and some of the other tuts here who have scored quite highly in these particular um subjects we've got videos which kind of summarize enhan topics and make them a lot more digestable and easy to understand we've got newsletters an at calculator which I spent way too much time on in high school but it is kind of a fun thing to see how you might stack up against the rest of the state we've also got articles um so lots of past students will write articles detailing how to score highly in particular subjects that they did well in or perhaps tips on how to like prepare for English or read your book effectively stuff like that and HS more so please check out our website I know everyone says check out the website and it's like yeah yeah whatever but I think it's a really really great resource and it's completely free so you can sign up be completely Anonymous don't tell anyone it's like nothing to lose so I recommend it and I always so parano this isn't recording okay it is recording good I'm glad yeah good and yeah we've got tons of more resources such as Cho smart steady guides and AD unlimited there'll be a little bit about that um where you're watching this I think and also a special thank you to lro Bey rmit Deacon UTS mqu um for sponsoring us cool okay a little bit about me I don't know why that's slightly cut off I'm so sad by that but my name is Angelica and I graduated in 2019 with a 97.25% uh I got a 49 study score for Bio 40p 47 for English and I recently completed biomedical science at M that was a three-year degree which I utterly adored I'm kind of a science nerd so I loved it and I'm now studying medicine at monach so this is my first year studying postgrad Med I know there are quite a few tutors who are doing undergrad Med but I'm not sure if there are many um today presenting who are doing postgrads if you've got any questions about that feel free to ask me in the chat and I can get back to to you I chew a bio PA and English with cart NATA notes and I love my cats this is marble and this is olly they're really kind of troubl making cats I also love longdistance running um avocado toast and cafes and people watching which people always ask me about but I just missed being outside during lockdown okay we're covering quite a bit today we're not going to do unit four but we are going to do quite a bit of unit 3 so we'll be looking at movement skills coaching practice and feedback biomechanics Energy Systems and acute responses and we'll look at this later on in the year so keep an eye out for that so ATP some of you guys may have never come across this before um I'm only deciding to teach it to my students this year now so I'm going to try and break this down in like an easy kind of way to understand hopefully um I have R DB break here but you guys can pause whenever you want to have a break I'm not going to be breaking though so we'll just get started so what is ATP so ATP is a really big part of the study design in PE um and in BIO too in chemistry if you're doing that but in PE it's really we talk about energy systems and how our body creates energy which we can use for muscular contractions so what is ATP it's a Denine triphosphate um it's a type of molecule which you kind of call the energy currency of the cell or of the human body and so we'll be looking um regarding ATP at the three energy systems in the body which produce this energy currency and so these three energy systems are going to be the atpc system anerobic glyos system and the Aerobic System so these three systems uh used in order to actually produce this energy currency ATP so ATP is uh it stands for adenosine triphosphate I not written that down here but you don't have to write that down in your exam because it's so long but I just find it useful to know ATP dening triphosphate Tri means three phosphate is is a phosphate molecule so it's an adenosine molecule plus three phosphate molecules if you've done a bio before you might actually recognize a the a um adenosine which is actually a nucleotide so when I realized that it blew my mind I was like what stuff in P crosses over with stuff in BIO and I was like what I thought that was really cool um anyways ADP is the only source of energy which is used for muscular contractions in our body so when one of the phosphate molecules breaks away from ATP it releases energy that we can use for muscular contractions so you can see here adenosine and three phosphate molecules what happens is that we actually break this Bond here and you'll know hopefully or you will come to know that lots of bonds in chemistry and biology contain lots of energy so when you break these bonds and snap them you actually release energy and so we can actually use that energy for our muscular contractions and so converting ATP three phosphates to ADP two phosphates and an inorganic phosphate molecule we snap that Bond and we actually release energy which we can use for our muscular contractions um so all three energy systems which I mentioned before in the first slide uh they all aim to rebuild ATP from ADP so basically it's like an entire recycling process whereby we have ATP we snap a bond and release the energy there and end up with ADP plus one inorganic phosphate and then we recycle that and make that ADP back into ATP and so once again we end up with a three phosphate molecule and so we can keep going through that process snap that Bond release it rejoin snap that b release the energy rejoin so pretty much we keep rebuilding that ATP up from ADP in order to ensure that we've got this energy source that we can snap that Bond and release it energy so yeah as I mentioned it pretty much gets recycled back into ATP and I just thought it was kind of cool that each person kind of uses their own body weights worth of 0p per day that so much ATP and each ATP molecule will be recycled about 500 to 750 Times Daily so this isn't really examinable but I do think it's quite interesting uh should probably keep a check of time okay so I think I started at 810 um let's keep going okay fuels so each of the three Energy Systems the atpc system anerobic glycosis system and the Aerobic System they each require some sort of fuel to produce the energy to help rebuild ATP and so the ATP PC system um is one of the first systems we'll talk about and it uses phosph creatine your teacher might refer to this as creatine phosphate vaa might refer to as CP or creatin phosphate or PC or phosph creatine any of these is acceptable uh SOA does accept a variety of answers for the name of this doesn't matter which name you use it's all the same thing which weer um we recognizes what is phosphocreatine so it's actually a chemical fuel I'm going to emphasize this point it's a chemical fuel not a food fuel so we'll be looking at Food fuels and chemical fuels throughout this uh lecture or lorial um but PC is a chemical Fu okay so make sure you know that because it might come up in your exam so it's actually used by the system called the atpc system so if you look at this it kind of senseful the adenosine triphosphate phosphate creatine system is kind of a big name but you can say ATP PC you should say ATP PC so when the phosphate and creatine break apart this produces energy that we can then use to reboard ADP into ATP so we use this phosphocreatine as a chemical fuel to recycle ADP back into ATP okay um so really keep in mind that we don't use PC for movement we use it to rebuild ADP into ATP and that snapping of the ATP third phosphate and transforming it into a DP gives us the energy that we use for our movements or our muscular contractions so keep that in mind please um give some water I'm still recovering from being sick so I'm really sorry if I'm not like super puppy if you've ever been to one of these before I get so excited about this topic CU I love it and I'm a nerd for it but right now I'm kind of not as peppy so I'm sorry about that but hopefully you feel okay with it anyway and the content isn't too fast or anything okay phosph creatine there's about 10 to 15 seconds worth of PC which can be sted the muscles and so it's actually used doing extremely high intensity activity such as sprinting as it's air would produce energy at a rapid rate so FEC stores can be replenished by staying still or performing a passive recovery and can also be replenished during steady state so just going to reide a few things you need to know here you do need to know that there's about 10 to 15 seconds worth the PC stored at the muscles that 10 15 seconds worth of PC is used to rebuild ADP into ATP that PC or fos creatin is used during extremely high intensity activity such as sprinting so if I just get up and start doing star jumps right now my body's going to be using that phospher creatine to rebuild ATP from ADP okay so I start exercising my body's going to break that third phosphate of the ATP into ADP and inorganic phosphate so it's going to snap that b to release that energy for my muscular contractions and my body's actually going to rebuild that ATP theine triphosphate by using phosphocreatine the chemical fuel because I've got about 10 to 15 seconds worth of that stored at my muscles say PC stores can be replac by staying still so if I just sit still for 3 minutes I restore about 90 um above 90% of my PC stores so think it's about 97% so really just performing a passive recovery sitting still or standing still allows me to replenish these doors this can also be replenished during steady state which is something we might look at later on okay as I mentioned before phosphate creatin is a chemical fuel however we have got a bunch of different fuels which are um actually food fuels not chemical fuels so phosph is the only chemical fuel we'll look at another really important fuel that we need to discuss is carbohydrates and so these are a food Feld that's found in many foods such as pasta bread rice potatoes grains like quinoa Gus stuff like that these are all carbohydrates so you do need to know if your foods which are carbohydrates main ones are Pastor bread rice but do keep a few in mind and be able to list them in case you get asked a question about this on the exam so carbs are used by the anerobic glycosis system which is another system we'll talk about and the Arabic system which is another system as a fuel so the atpc system does not use carbohydrates it uses phosphocreatine whereas the these two systems the anerobic glycolysis system and the Aerobic System both use it as a fuel so there are quite a lot of words that we use relating to carbohydrates so carbohydrates um well an Associated word we use is glycogen we also have glucose um and sugar so carbs glycogen glucose sugar these are all like Associated terms which we use not synonymously exactly but quite similarly to carbs they're all kind of like relating with they different forms of carbohydrate and so if I have some bread right now and I eat it um the carbohydrates in that bread are going to be stored in my muscle and in my liver as glycogen which is a kind of uh many branched structure so it's kind of like a convenient neatly packaged form of glycogen when I need energy that glycogen is going to be broken down into glucose so my body will break down that glycogen and release it in the blood as glucose or blood glucose or blood sugar so essentially carbohydrates are a type of simple sugar um because in their R form they are glucose a body will store it as glycogen when I need that Sugar my body will release it in the form of glucose it will get into the blood and be drawn or taken to the muscles or wherever I need it in order for that ADP to be converted back into ATP so similar to how fos creatin breaks apart to produce energy this break down of glycogen to glucose produces the energy needed to rebuild ATP from ADP I'm really dry right now I'm just Dusty cool so breaking down glycogen into glucose allows us to produce some energy this energy doesn't give us the energy for muscular contractions but rather it allows us to rebuild ATP from ADP and as such we can actually snap that Bond off the ATP and um use it to produce energy for our muscular contractions and do our star jums like go sprinting or anything else which is a muscular contraction so I mentioned before we've got about 10 to 15 seconds worth of phosphoric creatine stored at the muscles in terms of carbohydrates we've got about 2 hours worth of glycogen stored in our muscles and liver so events which are longer than 2 hours such as a marathon glycogen depletion may be an issue but unless you're running like more than 2 hours you're probably not going to have to like fuss too much about it because your body will store quite a lot of glycogen I don't know if anyone's ever done like cross country training or like half marathon or anything like that or full Marathon maybe but my cross country coach would always be like make sure you carbo load the night before and so you like have pass the night before your race because it means that we can store some excess glycogen in our muscles and liver for um energy which can be used to actually rebuild that ATP from ADP later on during the day or during our race so you can actually like Stir It Up a bit um I'm not sure we talked too much about that today but keeping stuff like this in mind is good to talk about in your exam so as excise intensity increases the use of carbohydrates to produce energy also increases so pretty much as exercise gets more difficult your body will rely more on carbohydrates to produce energy rather than other possible fuel sources sources such as fats uh and this is because carbohydrates take less oxygen to break down than fats making them more efficient fuel I didn't really understand this when I was in high school but your body um at rest like right now it's going to be burning quite a lot of fat and this is because fat requires lots of oxygen to break it down when you're running like during a race or half marathon or something you're not getting sufficient amounts of oxygen um particularly at the start and so your body is going to be relying on something which doesn't need a lot of oxygen to break it down and so carbohydrates actually don't need any Oxygen to break them down they can be broken down anerobic which means no oxygen required and so that's why our body tends to rely more on um breaking down carbohydrates as our energy source or our food fuel source cool um I see any questions but if there are any questions just put them in the chat and I will get back to you so we have another food fuel um just like carbohydrates so fats and lipids are a food fuel I said before the carbohydrates glycogen glucose blood sugar these are all like the same thing sort of we kind of use these words um in conjunction with one another um we have the same situation here with fats lipids free fatty acids trios glycerides um triglycerides all of these different words we kind of use as like an associated word for fat so keep that in mind so fats are another food F meaning that we can get them from the foods that we consume or in our diet just like cars except they're found in different foods so fats are found in things such as meat avocado I think avocado is a really good option to go for in the exam oils and butter amongst other things so fats as I mentioned before are a fuel used by the Aerobic System and this is because fats actually require lots of oxygen to break them down um like a H amount of oxygen and so when you're at rest like right now you're getting enough oxygen you're not out of breath hopefully you're just kind of sitting here taking lots of oxygen and so your body can actually utilize that oxygen to break down the fats fats must be broken down aerobically they need oxygen to break down so you can't break down fats using the anerobic vosa system okay uh just a bit more about fats in general they're stored as triglycerides in the muscle um so we eat some avocado this fat is stored in our muscles as triglycerides when we need that energy from the fat we break the triglycerides down into free fatty acids or ffas and similar to the breakdown of glycogen this allows us to produce energy which can be used to reild ADP back into ATP okay that's a lot um yeah so just to summarize recognize that it's a food Fu recognize a few foods that it's found in such as avocado oils butter know that it's used by the Aerobic System as it requires lots of oxygen to break it down and that it storees triglycerides in the muscles and then breaken down to free fatty acids as I mentioned before it's a preferred fuel at rest because right now at rest we've got sufficient otion to break them down effectively as exercise intensity increases the use of fats as a fuel decreases and if you think about this if I just get up and start running right now I'm going to be pretty out of breath okay and so that's because my exercise intensity is increased from like nothing to probably kind of a maximal level of I'm sprinting and so as a result my uh use of fats will decrease because I'm not getting sufficient amounts of oxygen to break down the fat and as I mentioned before our body can actually break down carbohydrates anerobic so it doesn't actually need um oxygen to break down carbohydrates and so when I'm kind of out of breath the body will be like you know what's a really good fuel use right now carbohydrates because no oxygen right so yeah as exercise intensity increases the use of fats as fuel decreases but the use of carbohydrates as a Fu increase I feel like I should set a timer cuz I'm going to be aware of how long I'm going on for and it's fine so food fuel contribution when a person is at rest fats are the predominant fuel source um during submaximal exercise carbohydrates contribute roughly two3 of the fuel source during maximal exercise intensity glycogen is a Sol Food fuel source and phosph may also be used but this is a chemical fuel carbohydrates the preferred fuel source over fats during exercise because they take less oxygen to produce the same amount of energy in comparison to fats as I mentioned before I'm just wondering if that's blocking I can't see I'm pretty sure I arranged no present yeah okay that's fine um it just look suspiciously like I'm blocking this if you if I'm blocking this it might just be for a few slides but definitely check the power PL like all l words and whatever there so yeah download the PDF after and have a look at it and I won't be in the way and this is just a nice little visual demonstrating our food fuel contribution so at rest I mentioned that fats contribute the majority of our energy um to Rebo that ADP into ATP so you can see here that's about two3 of the energy um or food fi contribution is done by fat oras one3 is by carbohydrates um whereas it kind of switches so you can see carbohydrates it's sub maximal exercise contribute the most with fats contributing about 1/3 and then for maximal exercise you can see that carbohydrates are the prominant pretty much contribute nearly all of that um the predominant food fuel um contributing to energy production or the rebuilding of ADP into ATP okay so we're going to spend some time looking at the ATP PC system anic glycosis system Aerobic System comparing the three Energy Systems fatigue recovery and then at the end if we have time I'm going to go with study techniques and so how I study for exams or how I do well in exams and what I'd recommend you do perhaps if you're seeking to get a really high study score just based on my own personal experience so firstly we'll look at the atpc system so this is something I've kind of mentioned a few times now um it's an anerobic energy system which means that it does not need oxygen in order to produce energy so as we touched on before the ATP PC system uses phosphocreatine or creatine phosphate sometimes you see this written down as ATP CP sometimes you see it written down as ATP PC doesn't really matter um vehic accepts both so um when PC splits into phosphate and creatine this releases energy that's used to rebuild ADP into ATP so the ATP PC system relies on simple chemical reactions occurring within the muscle and is therefore able to produce energy at a very rapid rate as well as using phosphocreatine the ATP PC system also utilizes a small amount of ATP that's already at the muscles hence the name ATP PC so you've got about 2 to 3 seconds worth of already formed ATP there sort of the muscles and this is used first and then we go to use our phosphocreatine so once that ATP has been depleted PC starts providing energy to rebuild ADP into ATP however there's only a limited amount of PC available at the muscles as well and this usually depletes about approximately 10 to 15 seconds so these PC STS can replace through use of a passive recovery which I mentioned I really thirsty so because of its ability to produce energy so rapidly the ATP PC system is predominantly used for physical activity of a very high intensity so anything which is about 90% the max heart rate or above so things such as short putut weightlifting 20 M Sprint if I just get up and start star jumping right now I'm going to be using the atpc system it's also used at the beginning of physical activity when the other energy systems are still warming up so if I get up and go run a 10K right now um my body is going to be using the atpc system first while the other systems are kind of like warming up and so for the first 10 15 seconds of my little run uh my body is going to be using the atpc system and then it's going to switch to a more um like anerobic type well sorry atpc isorobic but it will switch to another Energy System such as the anerobic glyos the system so while the atpc system is really effective at producing energy really quickly um like really fast instantly it only produces a very small amount of ATP and depletes really quickly okay so you produce energy very quickly but it's only a small amount and it depletes very quickly as well uh next system we're going to be looking at is the anerobic glycos system so it's another anerobic system as the name suggest and this means that it does not require oxygen to produce ATP again as the name suggests it uses carbohydrates or glycogen as its main fuel source when glycogen is broken down to glucose energy released that allows ATP to be rebuilt from ADP wondering if this is a timer does it have a timer I don't see any timer oh yeah 24 minutes okay cool we're going we're fine so yeah as the name suggests it uses carbohydrates or glycogen as its main fuel source you'll see like these names kind of give a hint as to what they use ATP PC use phosph anerobic glycolysis will use glycose something which is glucose which is carbohydrates um and then the Arabic system uses our Arabic FS which is fats but also um carbohydrates can also be broken down aerobically so Anor robic I just think a here a e r sounds like a means without without air system without air glucose system the system which produces energy without air and uses carbohydrates it's all in the name anyway this doesn't use oxygen um as a result it isn't able to fully break down pyic acid and remove it from the body so we'll look at this in a second um hopefully I've got a formula okay good I do so what happens is that we have carbohydrates we eat it it gets stored in our body as glycogen when we need this glycogen is gluc ose our body will break down the glycogen into glucose and release it into the blood because we don't have any Oxygen right now because our body is know running anerobic or out of breath not getting enough oxygen or sufficient amounts of oxygen to work aerobically we're working anerobic and what happens anerobic is that we have pyruvic acid being converted to lactic acid and so lactic acid is something which builds up in your muscles people often mistakenly think that it causes muscle soreness it doesn't what happens though is that there are hydrogen ions which are associated with lactic acid and these hydrogen ions can boit up in your muscles and it can cause um increased acidity in your muscles muscles require lots of enzymes to work there and so because of this increased acidity they are kind of messing with the environment which the enzymes used to function and enzymes are really sensitive to pH levels and so this increased acidity is kind of disturbing the natural pH of the environment and can interfere with the muscular contractions and this can cause that kind of like soreness or that fatigue you feel so I'll just sum up um pretty much peric acid is brn into lactic acid which isn't really a problem only that lactic acids bringing down into lactate and is associated with hydrogen ions hydrogen ions cause the muscles become acidic which inhibit the breakdown of glycogen and cause fatigue so you experience fatigue because of this this occurs as a result of the anerobic glycosis system so this pathway only happens anerobic so without oxygen when you have oxygen you have a different situation happening which we'll look at just really make sure to understand here that not neither lactic acid nor lactic causes fatigue like these these guys are innocent however um you have hydrogen ions and hydrogen ions also known as H+ ions or protons these are all the same names for H+ ions they actually cause fatigue and they're associate of the lactate so while people go like like they might measure the amount of lactate in the body and go oh yeah you this fatigued because of this the lactate isn't causing the fatigue it's kind of indicating like if you've got a high amount of lactate you've got a high amount of H+ ions produced as a result of this and so it's kind of indicating how fatigued you are okay so the lactate itself is innocent it's not causing fatigue it's the hydrogen ions or the protons or the h plus ions whatever you call it these are the actual cause the fatigue that fatigue fatigue fatigue I don't know why I said so weird and the elect inflection point or La a is the last point where electri entry removal um entry into and remov from the blood a balance and it's another um kind of a different thing so you can see here we've got blood lactate our body is producing lactate um or lactic acid which then gets converted to lactate also producing hydrogen ions but your body is removing it efficiently but as you increase your exercise intensity you'll get to a point where your body isn't removing enough lactate sufficiently and so it will start to build up and so after it builds up you're going to start to experience fatigue because you're building up lactate and you're also building up H+ ions and so the lactate Reflection Point is this little bit so the last flat bit before the graph starts to Peak upward and it's where lactate removal matches lactate production it's the last point at which lactate removal matches lactate production so beyond this point lactate levels are increasing exp exponentially and you're going to be experiencing fatigue okay so make sure you keep that in mind so lap or Latin inflection point is a pretty tricky concept and it is often examined so we try and go through it slowly so imagine we're going on a run together so we've been running for a while like 10 minutes maybe as exercise intensity increases say we're going up a mountain now so our speed increases or our intensity increases by going up that hill the body starts to use the anerobic glycosis system more heavily which makes sense because if you're increasing your intensity you're going to be more out of breath right it's harder for you to get sufficient amounts of oxygen into your body into your lungs up taken into the blood takeen to the muscles where you need them like it's getting harder because you're increasing your intensity so you're more out of breath so you've got less oxygen to work with as a result you're going to be working more anerobic and we know that anerobic activity uses the anerobic glycosis system and so you've actually got the production of paric acid which convert converted to lactic acid and then gets converted to lactate as such um you're going to be producing Associated hydrogen ions and so these hydrogen ions cause that fatigue um nonetheless lactate and hydrogen ions are building up before this point they were just kind of like steadily building up and being removed at the same kind of level so you just have like a constant one um or a constant level of lactate and hydrogen ions but once you increase your intensity you're going to be increasing the amount of lactate and hydrogen ions you have and so the body can only clear so much lactate and Associated hydrogen ions at a time and so once you hit the certain intensity um your lant hydrogen ions are going to be produced at a faster rate they can't be cleared by the body or that they can be cleared by the body and that will lead to fatigue right um really what you do have to understand here is just be able to identify where the lactate inflection point is inflection is like where a point changes Direction usually so you can see it's flat here changes Direction here so our graph starts going upward from that point on so that's the inflection point at which lactate starts building up so after this point lactate and therefore hydrogen ions will start to accumulate in the blood and the muscles and the hydrogen ions will cause the muscle to feel fatigued and that's why Blood lactate levels are a great indicator of fatigue at this point athletes will have to reduce the intensity of their exercise to an intensity below their lactate inflection point so you're feeling fatigued like we're running this race we're starting to feel really fatigued so we're going to have to reduce our intensity um so we want to reduce our intensity to such a level that we can actually start to remove that lactate and our body removes the lactate and hydrogen ions from our body naturally but we do have to reduce our intensity to kind of like help our body out therefore having a high High elate inflection point is extremely beneficial for endurance athletes so anyone who does like longdistance running or swimming you probably want a higher lacate flection point because it means you can work at a higher intensity without feeling fatigued for a longer period of time generally people have a elte reflection point at about 85% of your maximum heart rate although this can be trained and so with sufficient aerobic training you can actually increase your lactate inflection point and as a result um you will feel less fatigued for a longer period of time I can't see I'm hoping this is blocking um the anerobic glycosis system produces ATP at a fairly quick rate but not as quickly as the ATP PC system however it does produce slightly more ATP than the anerobic glya system so the quickest system so far is the ATP PC system and second quickest is the anerobic glycosis system um however the anerobic glycosis system produces more ATP than the ATP PC system so it's kind of like caveats associated with each system so one will be faster but the other will produce more so it really depends on your needs at the present time so the anerobic glycosis system is dominant during activities of a reasonably high intensity so anything about like 85% max heart rate and medum duration so about 10 to 10 10 to 60 seconds so if we go for a run um the first 10 to 15 seconds of our run is going to be supplied predominant by the ATP PC system because we've got 10 15 seconds worth of ATP and PC already started at the muscles from that 10 to 15 seconds up to about 60 seconds or a minute um the anerobic glyos system will be dominant okay and so this is dominant at pretty much 85% max heart rate and above to about 90 because anything above 90 we typically use the atpc system so like medium level duration events um sorry noise such as the 400 met R 200 me SL and repeated Sprints these will use the Arabic glycosis system so you often get asked a question your exam to name a particular event or sport which relies most heavily on the anerobic glycosis system and may go to for this is always the 4 met run because this is just literally one lap around your Athletics field it's over in about a minute so it will be like enlisting the anerobic glyos system most predominantly this is the energy system which will contribute the most energy production for this this event okay now we're on to our third me make sure can I just actually set a timer um okay I'm fine so the aerobic Energy System is our third system and it's the only one of the three energy systems that actually requires oxygen so it can use a variety of fuels to produce the energy required to rebuild ADP into ATP we've got carbohydrates which can be used or glycogen fats triglycerides and protein which we only use in like super extreme circumstances to produce the energy that we need for our aerobic Energy System so I mentioned before that carbohydrates can be broken down anerobic so they don't need oxygen but it is better if you break them down with oxygen because then they don't produce that fatiguing byproduct of hydrogen ions so when using carbohydrate glycogen is broken down into glucose and this produces the energy need to rebuild ATP so I think I mentioned this before when using fats we've got triglycerides being broken down to free fatty acids and this produces the energy needed to rebuild ATP also so what's the main difference between the anerobic glycosis system and the Aerobic System so the main difference is how pyic acids breaken down so as we just looked at with the anerobic glycosis system paric acid is broken down to lactic acid which then breaks down to lactate and hydrogen ions causing fatigue with the Aerobic System due to the presence of oxygen pyic acid is able to be broken down into body products that don't cause significant fatigue such as water carbon dioxide and heat so before in the anerobic system pyic a is bring down the latic acid bring down into lactate and hydrogen ions and those hydrogen ions mess with the acidity of our muscles and cause fatigue in this case here we don't actually produce lactate um that pyic acid is straight up broken down into byproducts that don't really cause a bunch of fatigue so these byproducts are water carbon dioxide and heat and they don't mess with our muscle acidity or anything so yeah see here glycogen bring down to glucose glucose bring down pic acid but no lactate is being produced rather we've got carbon dioxide water and heat and this is actually a formula for cellular respiration or air cellular respiration so if you're doing bio look out for that um the Arabic system produces ATP at a far slower rate than the ATP PC system and anerobic glyos energy systems therefore it's dominant for activity that's performed at a sub maximal intensity such as jogging and other activities that occur at less than 85% Max height rate and have a longer duration so the Aerobic System produces far more ATP than either of the other Energy Systems therefore the body will always produce energy aerobically when possible as it produces more ATP and leads to less fatigue okay so while the ATP PC system is the faster system it produces the like tiniest amount of ATP andb system is kind of medium like it's faster than aerobic and it produces more than the atpc but it's not as fast as atpc and it doesn't produce as much as the Arabic system and then finally we've got the aric system which is the slowest Energy System but it does produce the most ATP and leads to less fatigue as well so we kind of want to prioritize this one because that fatigue can be quite debilitating so it's important fact to keep in mind throughout the year as we look at acute responses and chronic adaptations which are all focused on getting more oxygen to the muscles so that ATP can be produced aerobically as exercise intensity increases the Arabic system will begin using carbohydrates rather than fats more predominantly as an energy source this is because carbohydrates despite producing less energy than fats actually take a lot less oxygen to break down they can actually be broken down without oxygen which is really useful so Arabic glycolysis is a term used to describe the Arabic system using carbohydrates as fuel Arabic lipolysis lipo fat lipolysis liis means to breakdown so we've got breaking down fats using oxygen or air um is a ter used to describe the Arab system using fats or lipids as a fuel and it's slower than aerobic glycolysis so the breakdown of fats takes the longest amount of time but it produces the most energy okay well we're getting through this so quick how long have we been on full nearly 40 minutes um okay comparing the three Energy Systems this is just a really intense looking diagram but it kind of summarizes what you need to know uh you don't actually need to know the number of ATP be produced being produced by each system um Ian you can memorize that if you want but maybe don't feel up the precious brain space or stuff like that uh but we have covered all of this already pretty much um so the sorry anerobic systems are um the atpc system and the anerobic glycosis system and the Aerobic System is obviously aerobic so these two don't need oxygen and this one needs oxygen as it is aerobic you've also got a bunch of different fuels used by each system you've got phosph creatine here glycogen glycogen chloric chloride and protein being used by the Arabic system as I mentioned before proteins kind of used only in really extreme circumstances so we don't really talk about it that much in PE um but we definitely talk about glycogen triglycerides and phosphocreatine keep in mind that phosphocreatine is a chemical fuel whereas carbohydrates and fats are food fuels what intensities do we need so for the ATP PC system we typically have a very high intensity of about 95% max heart rate and above um with the anerobic glyos system we have intensities of about 85% max heart rate to about 95% and then for the Arabic system anything less than about 80 to 85% max heart rate and it'll be using the system total duration this says 10 seconds but I typically say 10 15 seconds the anerobic glycosis system is about 75 seconds roughly 60 to 75 seconds and then the Aerobic System is about 60 seconds onward so um if you're running for 20 minutes you're probably going to be using or relying most heavily on the Aerobic System so when is a system dominant during physical um activity so the ADP PC system is dominant within the first few seconds of starting um anerobic glyos system is dominant know if like that first minute and then onwards you've got the Arabic system being the most dominant what about byproducts being produced so with the ADP PC system our main byproducts are inorganic phosphates and ADP and these can kind of interfere with muscle acidity also a little bit um it just kind of impede upon contractions I think so they are slightly fatiguing the worst contributor to fatigue is really that those hydrogen ions so lactate hydrogen ions and ADP do you recall I know I've said it like seven times already but the lactate itself doesn't cause fatigue rather it's the hydrogen ions which do that you've also got ADP um being produced once again and that can contribute to fatigue as well in terms of the Arabic system and fatigue these aren't really massively fatiguing factors but you do have some byproducts being produced and they are carbon dioxide water and heat and so that heat can cause you to overheat that was a strange sentence but once you start overheating our body is going to be redirecting blood FL to the skin in order to enable you to sweat and cool your body down and so that can actually lead to fatigue as it red diverts blood and oxygen which is in the blood from going to the working muscles and actually takes it to your your skin right it wants to evaporate the water and cool your body down and so in red diverting that blood flow we actually have to rely more heavily on anerobic syst at the muscles while you are overheating and so that can lead to more fatigue caused by those hydrogen ions because you're relying more heavily on the anerobic glyos system um yes I think that was all I needed to mention about that speed of production we know that the ATP PC system is the fastest then you've got the anerobic glyos system and finally the Aerobic System uh regarding the amount of ATP produced though the Arabic system produces the most with the anerobic second and the ATP producing very minimal amount but it produces it very fast which can be quite useful sometimes um don't memorize these numbers you don't need to know them but I do want to draw your attention to how much ATP is produced by triglycerides you can see the triglycerides produce the most ATP energy and even though glycogen produces quite a bit you can see Tri glucd produces like a ton um however it does take a while for the triglycerides to actually be broken down because they do require quite a large amount of oxygen okay so that's something to keep in mind so as exercise intensity increases I think I already had this slide but we start using carbohydrates more than fats because carbohydrates don't require oxygen to break down whereas fats do um so fats require a lot more oxygen to break down the carbohydrates aerobic glycosis helps us break down or is the process in which we break down the glycogen or carbohydrates and aerobic glycosis is that term we use to break down fat and this requires quite a lot of at um I'm sorry um of oxygen and but it does produce a large amount of ATP however it is quite slow we are literally zooming through this how many slides do I have today okay I've got 100 nearly 100 we are fine we are fine okay now we're on to fatigue so basically if our Energy Systems run out of fuel they aren't going to be able to produce ATP and we will feel fatigued so f can refer to the depletion of any of the fuels used by the energy systems so for the ATP PC system fuel depletion refers the refers to the depletion of ATP stored at the muscles which takes around 2 to 3 seconds followed by the depletion of PC which takes around 10 to 15 seconds so after these FS are depleted the anic glycosis system will have to be used more heavily likely resulting in more fatigue I recently moved um rurally from meded school and I feel like the air is just drier here and I get really dehydrated more easily I don't really know if I'm making that up or if that's real but that's what I'm feeling okay so depletion fuel depletion means that we can't produce ATP and we'll feel fatigued so yeah for the ATP PC system fuel depletion means that we've lost the ATP and PC there and so we've got to wait a little while in order to replenish these stores I did mention before that we can replenish these stores by waiting 3 minutes and this will replenish about 97% sorry 3 minutes is about 97% replenishment of fos creatine another source of fatigue is the buildup or accumulation of metabolic byproducts and so the buildup of these metabolic byproducts is a source of fatigue for the two an Energy Systems so increase ADP which is adenine diphosphate and inorganic phosphate or Pi levels which are caused by the breakdown of ATP and these reduce muscle contraction force and therefore cause fatigue lactic acid um we know can cause fatigue sort of like I mentioned before that it's not the lactic acid itself which is the contribut of fatigue rather the hydrogen ions which are associated with it so as we saw earlier lactic acid accumulates when an athlete Works above the LA inflection point remember the lact lactate inflection point is the last point at which um lactate entry and removal into the blood balance after this point it will start increasing so lactic acid then breaks down to lactate and hydrogen ions the hydrogen ions make the muscle acidic and colose fatigue lactate levels are a good indicator of fatigue but they actually cause fatigue like can actually be used by the LI to produce more glucose which can then be used for fuel another source of fatigue is actually elevated body temperature so all the chemical reactions that occur in our muscles can cause Heat be released um and this can cause our body temperature to increase particularly on a hot day so I kind of touched on this before so imagine you're out running starting to overheat I overheat really easily like when I start running um so my body temperatur starting to increase so my core body temperature is increasing or overheating during physical activity and as a result my body is like oh no homeostasis I need to like restore my body back to its like kind of regulated State and so what happens is that it sends more blood to the skin in order to help us sweat and cool the body down and so it red diverts blood flow to the skin so you've got VOD dilation um going to the skin and Vaso constriction going to muscles away from the skin so we really want to like redirect the blood like make the the pipes of blood going toward our skin like a lot bigger right and so it sends more blood to our skin uh we'll start to have evaporation there and we'll have like lots of plasma and this will cool down the body so while this is a effect of it cooling down the body it actually means that less blood and therefore less oxygen ends up flowing to the working muscles what is the point like of blood why do we have blood it's to get the oxygen to our working muscles right and we get that oxygen to our working muscles so that we can work aerobically if we're overheating though we've got to redirect that blood to cool us down so we redirect the blood to our skin evaporate it to cool us down but it means that the blood and thus the oxygen is not going to the muscles but rather to the skin therefore we actually have to produce more energy and a quickly and then we have to rely on the anerobic glycosis system and so we know that the anerobic glycosis system produces lactic acid which is then Convent to lactate and associate with those hydrogen ions which are quite fatiguing and so kind of have a chain reaction of events which leads to more anerobic energy production and causes more fatigue so you kind of see that elevated body temperature um is kind of a cause of fatigue in the Aerobic System but the reason it's a cause of fatigue is not not because of the Arabic system itself but rather because overheating means we've got to redirect blood flow and that blood's not going to our working muscles so we're forced to work anerobic and hence fatigue anerobic that makes sense um maybe read that a few times to try and like work through it in your head and you'll see that it's really the anerobic system at fault here we are fine very thirsty we have more water okay so I've got a nice summary table here kind of identifying the likely cause of fatigue associated with each Energy System water so regarding the ATP PC system the most likely cause of fatigue is fuel depletion so we've lost um phosph cortin and ATP so We R get a little bit sort at the muscles um to supply the muscles instantly with the anerobic glycosis system we've got accumulation of metabolic byproducts including hydrogen ions inorganic phosphate and adenosine diphosphate and regarding the Aerobic System we've got fuel depletion um so we've got loss of glycogen and fat and we also have elevated body temperature which just leads to increased Reliance on the anerobic system which I just touched on okay on to recovery and then we'll look at acute responses which is like our second part so we'll look at two types of recoveries active recoveries and passive recoveries so an active recovery involves performing reduced intensity activities at the end of a training session so you might have a really intense game of footy um you might have an active recovery afterward and it might be something like slowly jogging around the sports over or walking around for a bit a passive recovery on the other hand involves sitting still or standing still um as I mentioned before a um phosph creatine replenishment requires a passive recovery which is the most effective so 70% of PC stores can be replenished after 1 minute of a passive recovery and about 98% can be restored after 3 minutes so if you have just run 100 m probably going to be using up all your PC stores CU it's only there for about 10 15 seconds remember you want to restore your PC stores what you want to do is do a passive recovery and so you kind of sit or stand still for a total of 3 minutes and this replenishes about 98% of your PC um kind of keep sitting still for a bit longer and her 100% of it the type of recovery though does depend on the activity that you just conducted and the energy system which was most predominantly used during the activity you just conducted so as I mentioned before the atpc system requires a passive recovery in order to replenish that phosphocreatine the other two systems however the anerobic glycosis system and the Aerobic glycosis System these actually require an active recovery so um I don't think I discuss more about this I would just discuss it out loud so the ATP PC system produces energy at a very rapid rate and as use tubes of a high intensity we need to undergo passive recovery in order to replenish PC stores the anerobic Leos system produces fatigue causing byproducts so as I mentioned before the gabic glyos system breaks down uh glycogen into glucose um this glucose breakdown um or this this respiration breakdown respiration breakdown this respiration actually leads to a byproduct called paric acid being produced and in the case of anerobic respiration or the anerobic glycol system we actually have that paric acid being broken down into um lactic acid and th lactate and this lactate is actually stated with those hydrogen ions how do we get rid of these hydrogen ions your body will actually just metabolize it eventually um but it does take a while and so in order to actually cycle out this hydrogen ions you need to undergo an act of recovery and so just walking around the oval for a bit or doing a lap around the oval a slow jog something like that this is a pass um sorry an active recovery and will allow us to cycle out those metabolic fatigue and byproducts the Arabic system um also requires us to undergo an active recovery probably because you've actually relied quite heavily on the glya system if you're assing to use AIC system predominantly so you actually probably do have quite a bit of accumulation of those metabolic ftig byproducts here and so you do want to cycle them out by undergoing a p an active recovery so especially if you have an elevated body temperature because if you know that if you do have an elevated body temperature you've actually got that rediversion of blood to the skin and therefore increased um Reliance on the anerobic system and therefore increased production of those hydrogen ions and in organic phosphates and ADP and these do need to be cycled out metabolically and an active recovery can assist with that cool okay now we're moving on to aute responses we're doing so well with time so I'm actually probably going to spend quite a bit of time at the end kind of discussing study techniques and tips um yeah it's such a it looks very I don't know it looks interesting how I might say on the screen um but yeah okay we'll look at what is an acute response we'll look at respiratory acute responses cardiovascular cute responses and muscular cute responses water so when a person begins exercise the body makes a number of changes and these changes are known as acute responses acute just means small if you think of like acute angle it's a small angle um I just think a cute a cute like cute I just think a small thing is cute like a puppy Rick something like that um so I just think small acute means small it also means kind of short so acute responses are short-term changes so acute responses only last for the duration of the exercise and the immediate recovery per period and they are short-term changes to the body that occur during physical activity uh we'll look at in unit four chronic adaptations and these are actually long-term changes to the body that occur as a result of consistent training but right now we'll be looking at acute responses and there are quite a lot of them so I will try and work through them a bit slowly so a key understanding here is understanding that muscles need oxygen to work the harder the physical activity the more oxygen they need we mentioned before that they don't need oxygen they can work anerobic but that this produces lots of fatigue and so your body is like no I don't really want fatigue obviously I actually want to do something which doesn't require as much fatigue and so they want to rely more heavily on um aerobic systems so nearly all of these acute responses aim to increase the amount of oxygen that can be supplied to the working muscles for the duration of the physical activity this is super important as more oxygen means that more ATP can be produced using the aerobic energy system which produces a greater amount of ATP than the anerobic energy systems and causes far less fatigue okay that was a pretty big slab of tag so pretty much what was saying here is ultimately our acute responses are one to increase amount of oxygen going to the muscles this means that we can use more oxygen Energy System which is the Arabic system therefore we use less an arobic system therefore we produce less fatigue and therefore we can work more effectively and so I'm going to start sounding super repetitive because I'm just going to start like reciting this um like more emphasis or more use of the Arabic system therefore less requirement of the an Arabic system therefore less fatigue is produced or sorry less metabolic fatigue and byproducts produced therefore more effective energy product something like that you start like repeating it over and over and over and over again and so hopefully you'll get an understanding of it as we progress through so we'll look at respiratory acute responses so these refer to changes in the respiratory system that occur as as a result of physical activity and these changes occur in the lungs and Airways around the body they generally aim to get more oxygen into the body which can then be transferred via the cardiovascular system to the working muscles allowing more ATP to be produced aerobically so respiratory just refers to like breathing systems so the lungs so one of our acute responses is increased respiratory rate um I think an easy way of memorizing a lot of these acute responses is kind of imag in yourself like getting up out of the exam room and going for a run if you just think about what happens to your body when you start going on a run you'll think okay I'm starting to get a bit out of breath okay what is that that's an acute response if I'm out of breath what system is it it's going to be the respiratory system um why would I be out of breath well your body is trying to get more more breath more oxygen in okay so respiratory rate is a number of breaths taken per minute so respiratory bre sorry respiratory rate is breaths per minute when exercise starts respiratory rate increases and this results in more air entering our lungs so we start getting out of breath and increasing our spiritual rate because we're starting to use quite a lot of energy and our body needs to make more so it goes wow we need more energy we need more oxygen therefore because we need to use our airobic system so it starts to um breathe faster increase our respiratory rate and therefore results in more oxygen getting into our body I really thirsty so hopefully that would make sense got something else could tile volume and this is the amount of air inhaled in a single breath so that's the amount of tidle volume you have like taking in a single breath thinking of how much that volume of air there that's tidle volume so as exercise begins tile volume will increase tile volume ples at a high but not a m maximal intensity so ventilation is another um respiratory acute response and this actually has a formula associated with it and so ventilation is the product of respiratory rate and tidal volume so V equal TV * RR it's really annoying that you have to memorize formulas but you have to do it anyways and you don't actually get a formula sheet so it is something you do have to remember um I don't really have any good pneumonics for this I would just pretend like I didn't really get a Starbucks I don't really like it very much but they have like ventti cups of Starbucks and I would like pretend like someone's initials with TV or RR both of them on a Starbucks cup and so I would like draw out a little cup be like it's a veny size cup with tvtimes r r and that was just kind of memonic to help me remember this because it's just an annoying formula to remember so if you come up with something which is a better neonic at remembering this formula let me know in the chat so I can tell everyone else um but yeah I I don't really have a lot of pneumonics for this it's just really trying to memorize the formulas and it's kind of not fun but you have to do it anyway because it'll be in your exam so hopefully you can come up with something anyway if ventilation is a total amount of air inhaled per minute you can see breaths per minute is respiratory rate and air per breath is TI of volume and this is air inhaled per minute which is a combination of them both an increase in respirator or TI of volume will result in an increase in ventilation obviously so I increase this one or this one it's going to increase this one meaning that more air and therefore more oxygen is able to enter the lungs where it can be diffused and transported via the blood to the working muscles ventilation increases linearly with exercise intensity until it reaches the ventilatory threshold and so this occurs at about 65 to 75% of maximum height rate sorry maximum oxygen consumption and after this point ventilation will increase more slowly cool um hopefully this makes sense just touching on this one so when you breathe in the air enters your lungs it actually diffuses through the alviola um into your bloodstream and it's transported into the blood the blood then carries the oxygen in something called hemoglobin which is like an oxygen carrier molecule and it transports through the blood to the working muscles but it will then transfer it to myoglobin which is like the oxygen carrier and the muscles and once it's there you can use that oxygen to actually facilitate aerobic um uh respiration or that Aerobic System actually creating energy and so we can create energy aerobically there um yeah so hopefully that makes sense I feel like we are really ahead of time we have like a whole hour left and only like 30 slides left okay I might spend a bit of time looking at things like this although I don't really like this diagram very much um I guess what it's saying is it's disgusting your ventilation and at sub maximal exercise you know you won't be majorly out of breath be I mean your your breathing increased okay we'll start from start say your resting breathing rate or um ventilation is at 20 um arbitrary units I guess or 20 um Vol lers of air per minute something like that um as you increase your intensity to the sub Max you can see that it will rise to about 100 um and then it will start to decrease as you recover right and it will go down as you recover however when you are exercising maximally it's going to keep increasing you do need a higher amount of oxygen in order to facilitate the exercise that you are um engaging in okay and so you're actually increasing amount of oxygen your body is requiring here you can also see that like as you start to recover um it's going to dip down quite steadily but it will actually take a longer period of time before it can refer return back to our pre-exercise level as a sub maximum one gets a bit faster so seeing how um increased intensities mean kind of an increased return time or an increased recovery time is associated with it you can see there's a slower decrease associated with the maximal intensity as opposed with the sub maximal intensity exercise another respir acute response is something called increased pulmonary diffusion I just think pul when I refers to lungs what I always do in um like biology and stuff I always look at the atmology of words and so if I'm stuck on a word and I can't quite like grasp its meaning I'll look up pulmonary atmology and it usually has some like interesting phrase tied to it and I hope going remember a bit better like acet acetabulum I think um which is made up of your like pubic bones it actually means vinegar cup because it was used in like rights they would drink vinegar out of the three bones and so something like that helps me remember things so if you're having trouble with these names like pulmonary or um I'm not sure this area study has quite a lot really of like intense long words like that but if there are definitely look up what they mean or look up the atmology and then that'd be a nice story associated with them and it might help you to remember it anyway the last so cute responses um increase Spirit rate tile volume and ventilation they all allowed more oxygen to enter the lungs during exercise however it's not until the oxygen actually enters the blood that it's able to be transported to the working muscles and used by the aerobic Energy System so in order to allow the oxygen to enter the bloodstream we've got a process known as defusion taking place and diffusion means the passive movement of gases from an area of high concentration to an area of low concentration which seems quite technical but I will try and explain that next page anyway this Exchange of gases occurs somewhere called the alveola in the lungs so our lungs have these little Branch structures two lungs right um the branches kind of like pet her out and they end up with these little like grap like sacks um very small airfill sacks that look like grapes these are known as the Alva and so what happens is that the oxygen gas goes down to the alviola and it diffuses from these alviola into the bloodstream which is kind of like next to it capillaries and stuff there and during diffusion gases move from an area of high Concentra to Ana of low concentration so there was a nice diagram that which I will use in a minute as there's lots of oxygen in the lungs it moves into the capillaries of the bloodstream so capillaries are really thin vessels and they're really good for diffusion so they're super thin so gases can quite readily cross them so carbon dioxide moves from the bloodstream where there is a high concentration to the lungs where there is a low concentration so essentially you've kind of got the stopping of gases occurring here you breathe in you take in oxygen the oxygen goes down your lungs it goes into the alviola it will then diffuse from the Alva into the um bloodstream by the capillaries you've got carbon dioxide so carbon dioxide is already in your blood because it's already um you know the Oxygen's been extracted from it and so the carbon dioxide Will is at high concentration your bloodstream it will actually go to your lungs and it will move from the bloodstream into the lungs you kind of have carbon dioxide and oxygen swapping over so carbon dioxide be exhaled out and the oxygen will go down into your bloodstream and go to the working muscles where it needs to be used this then allows the oxygen to be transported to the working muscles and the carbon dioxide can then be exhaled and this increased diffusion results from an increase in the surface area of the alola so alola are very small things with a very small um volume have a high surface area to volume ratio and therefore they're really good exchanging gases alol are like highly specialized at this this is what an alola looks like it's like a grape like structure it's covered in lots of um capillaries the capillaries are those small vessels very thin very good exchanging gases so you breathe in oxygen enters your lungs gets into the alola you've also got um carbon dioxide returning from your body it wants to leave the bloodstream and so these alv are covered with capillaries these capillaries are very thin very good at diffusion and so the carbon dioxide goes from an area of higher concentration there's a higher concentration in the blood here enters the alola it to be exhaled out and the oxygen will move from here with a high concentration to an area of low concentration in here and so it will swap so they essentially swap places allows us to efficiently get rid of the carbon dioxide and use that oxygen gas and take it to our working muscles um so you can see here we've got our lung sack the alola we've got our capillary on the outside um deoxygenated Ro blood cells get rid of that carbon dioxide and the alola air here is full of oxygen which then gets substituted into the bloodstream and that goes up to the working muscles um really need to know much about the rest of these uh parts of the the Alva um but yeah pretty much exchange of gases occurs at the alv and this allows us to um effective sorry effective substitution of gases and allows us to bring that oxygen to the working mus muscles thus enabling us to work aerobically or more effectively aerobically okay moving on to cardiovascular key responses oh no oh we are on cardiovascular so cardiovascular acute responses refer to changes in the cardiovascular system which occur as a result of physical activity these changes occur in the heart and blood vessels around the body and they generally aim to get more blood and therefore more oxygen to the working muscles allowing more ATP to be produced aerobically cardiovascular you just think cardio means heart vascular means like vessels blood vessels so cardiovascular cute responses refer to small responses in response to exercise which affect the heart and the vessels but blood systems okay so that kind of helps me to remember it so once again looking up the atmology of words um might help you to like remember what these words mean so one of our main cardiovascular cute responses like if you imagine going out running what's the first thing you're going to notice probably that you're out of breath second thing is probably your increased heart rate you'll feel your blood pumping right you'll start to like be more flush cuz your blood's pumping harder stuff like that so increased heart rate is an increased sorry is a cardiovasular ular acute response to exercise what is heart rate it's the amount of time the heart beats per minute so it's taken in beats per minute um I give you a bunch of formulas all throughout these lectures um if you come to them throughout the year I'll give you a bunch more formulas too but yeah we don't need to know all of these formulas really um like you don't have to calculate anything on the exam except for this one formula here and this is our maximum heart rate so the maximum heart rate of an athlete is equal to 220 take away their age so I'm 21 so 220 take my age 220 take 21 um you guys should have figured that out so you're not allowed to calculator in the exam I'll give you really simplistic calculations like 220 ti8 stuff like that um but this is the only the only formula the only calculation you need to know to do and it's come up in the exam before so yeah keep that in mind um if you're like 18 do 20 tick 18 your maximum heart rate is going to be something like 202 beats per minute approximately okay so keep that in mind um by increasing heart rate more blood is able to be circulated around the body which makes sense what's the point of our heart like it beats right it beats to pump blood around the body why do we need blood going around the body because that blood brings with it nutrients and oxygen so we can actually deliver that oxygen to the working muscles as such we can actually produce more ATP aerobically as opposed to anerobic in doing this what we do is we actually increase kind of Reliance on the Aerobic System as opposed to the anerobic glycosis system or the anerobic or the atpc system why don't we really like the anerobic systems well because they cause fatigue remember they actually result in the production of metabolic fatigue and byproducts because that uh carbohydrate is broken in from glycogen into glucose into pyic acid because we're working anerobic that paric acid is going to be broken down into lactic acid and hence lact and also produce those metabolic fatiguing byproducts hydrogen ions and those hydrogen ions actually are going to interfere with the acidity of the muscles and cause fatigue and so that's really not good for us causing fatigue is not going to be conducive to your exercise and so we really want to avoid that as much as possible hence you can see that increased heart rate is an effective measure at kind of circumventing that okay that was kind of a long spill um just going on about increased heart rate more blood more oxygen more Reliance on Aerobic System n Reliance on anerobic system and it's kind of a tedious thing cuz I'm going to go through it like 10 more times throughout this lecture today but it's going to be something that comes up in your exam you need to be able to say something like that or to that effect on your own paper because it might be something worth eight marks when they ask you to discuss why we want these cardiovascular acute responses to occur or respiratory acute responses to occur like what is the point of them essentially to get more into your working muscles that you actually rely more heavily on the a RO system as opposed to the anerobic system okay so you really want to keep that stuff in mind um there's a direct linear relationship between exercise intensity and heart rate hopefully you'll like recognize this you run harder your heart rate increases and it increases to about a maximal rate of 220 take away your age okay um straight FL you missing another cardiovascular C response so it's the amount of blood that leaves a left ventricle the heart per beat uh left ventricle is really important because it's is the Chamber of heart at which the blood like leaves and enters the bloodstream so you do need to know that left ventricle of the heart for St volume I know it's really a through increasing strap volume more blood and oxygen is able to be circulated around the body and therefore more oxygen is able to be delivered to the working muscles so if you just think about it the amount of blood that leaves the left ventricle heart but beat if you increase the amount of blood that leaves you increase the amount of oxygen which also leaves therefore you've got more oxygen going to the working muscles therefore you've got increased Reliance on the Aerobic System as opposed to the anerobic system therefore less production of metabolic fatig and byproducts particularly the hydrogen ions which are associated with lactate which are a byproduct of the anerobic system and therefore you've got less fatigue being produced so that's why we want more aerobic Reliance okay very repetitive um another formula we do need to memorize here increased cardiac output cardiac outputs also written down as Q um and its formula is qal SV * HR so it's actually a product of heart rate and Str volume multiplied by one another what is cardiac output is the total amount of blood that leaves left ventricle permanent so you can see it combines these two previous formulas heart rate which is beads per minute and St volume which is the amount of blood which leaves the LI ventricle so ultimately IC output is the total amount of blood that leaves the left ventricle per minute so productive heart rate and stroke volume so an increase in heart rate or or and um and or um an increase in stri volume are going to result in increase in cardiac output an increased in cardiac output means that more blood is circulated around the body and more oxygen is able to be delivered to the working muscles allowing more ATP to be produced aerobically okay so ultimately you can e increase either straight volume or heart rate and this increased cardiac output also what does this do this increases the total amount of blood that leaves Le inle per minute therefore we've got increased oxygen going to our working muscles therefore got increased Reliance on the Aerobic System as opposed to the anerobic system um therefore less Rel to the anerobic glycosis system means less production of metabolic fting by products such as lactic acid and its Associated hydrogen ions which cause fatigue therefore we've got less fatigue and more effective exercise um or energy production without the cause of fatigue okay I know it's repetitive and I'm going to keep saying it but you have to know this and you have to be able to write something to that effect for the exam I feel like I'm actually just saying the same thing over and over again sorry I know it's annoying but this will hopefully help you for the exam another cardiovascular acute response is increase blood pressure um so exercise results an increase in systolic blood pressure uh you don't need to know too much about systolic versus diastolic the definitions are here anyway so systolic blood pressure is the pressure in the arteries after the blood's been pumped out of the heart diastolic blood pressure is the pressure in the arteries when the blood has returned to the heart for the next beat I'm trying to remember my pneumonic for it I made up in like first or second year of uni um okay systolic I remember now so systolic I think cic being the blood pressure after the heart's been squeezed so if you squeeze the heart right like you just shoved the blood out of it so it's squeezed out syic squeez just think SS dioic I just think dead like if you're dead like you're like resting right it's like a resting blood like there's no pressure being applied there it's just the the blood pressure in the in the arteries when the blood returned to the heart for the next feed so I don't think you really have to know that anyway um but if you do buy a med or something like that later on on that may be useful to know ultimately um increased blood pressure um is useful as a cardiovascular response because it means more blood gets to the areas we need therefore more oxygen gets to the areas we need therefore we've got increased blance in the Aerobic System as opposed to the anic systems therefore less production of metabolic fitting byproducts such as the hydrogen ions associated with lactic acid which lead to increase acidity in the muscles and cause fatigue so once again it's good to be producing more energy aerobically we've got something called increased Venus return so it's really important that any increase in CTIC output is matched by an increase in Venus Return of the blood to the heart so cardiac output remember has a formula of steric volume Times by heart rate we actually need to return this Blood back to the heart and we actually return blood back to the heart via the veins and these are a network of vessel um which return blood back to the heart and there are three main mechanisms oops I can't the next page um yeah so veins have valves they return blood back to the heart it's really important if you just imagine you're pumping blood out of your heart and it's not returning like you don't have any more blood going to the lungs and circulating around your body so we need Venus return we need to return that blood back to the heart otherwise that blood's just going to pull somewhere and never come back like you don't even really think about this until you study it but yeah we need to ensure that that blood returns back to the heart there are three main mechanisms one of them is Vaso constriction and so veins can constrict and this forces the blood to move towards the heart okay so veins kind of like stiffen a little bit and that forces the blood to go back toward the heart uh another one of the mechanisms is called the muscle pump or the sceletal muscle pump um if you're sitting here watching this lecture right now I want you to kind of like raise one foot on your tip toe so stand on tip toe on one foot okay you can feel the muscles in the back of your calves Contracting together I have not done my anatomy homework so I can't tell you what muscles they are but lifting your leg up you can feel those muscles contract right they they get T and tight so what happens is that when muscles contract veins are squish together so lifting your leg up just sign on tiptoe there is squishing your vein this actually forces the blood inside of that vein to flow back toward the heart within the veins there are one way valves to prevent the blood from flowing back down towards the muscle and continue to flow it towards the heart so lift your leg up you constrict it with those muscles forces the blood to go back toward the heart there are veins which kind of shut behind it and so there's no backflow and so the veins are forcing the blood to go all the way back to the heart I've got another mechanism which can return blood back to the heart via the veins and this is known as the respiratory pump so when you breathe in the diagram actually increases pressure in the abdominal area so you've got an increase of pressure in the abdominal area and this forces the veins there to be emptied towards the heart so these different pressure gradients contribute to blood flowing back to the heart and so when you breathe out again the pressure is released and the veins fill with blood again s continually breathing actually activates the respiratory pump and helps return blood back to the heart V the veins um I feel like this is quite AIG getable part of PE these three mechanisms of Venus return you do need to know them for your exam like you need to be really quite well vers in them and be able to discust them quite easily so do be aware spiritual Trump refers to the diaphragm increasing pressure in the abdomen forcing blood to ref um back towards the heart VI veins the sceletal muscle pump or the muscle pump is when you constrict your muscles and it forces the blood in the veins um to be forced back to the heart because it squishes the veins the vein are oneway valves they get squished blood Force upward vein shut behind them and so the blood must go back toward the heart and the last one which is the veins constricting so vasay constriction or vein constriction veins constrict or stiffen up a little bit and this forces the blood to move back toward the heart how we're going for time we're going good we got plenty of time um decrease blood volume so during physical activity the volume of our blood or the amount of blood actually decreases okay so while more blood is being pumped around our body every minute some of the plasma in our blood is actually lost to sweat and this results in decreased blood volume so I'll just try and break this down a bit more um I don't know for a really long time I would just like yeah blood's red it's just red blood cells but blood is made up of a bunch of stuff so um there are red blood cells white blood cells and blood and also um plasma which is like a fluid a fatty fluid type stuff so during physical activity when our body is overheating we need to cool down so I've already mentioned this before but our blood will redirect blood flow toward our skin and so what happens is that you've got some vasid constriction um Vaso constriction and Vaso dilation and so you'll have dilation of blood vessels going towards your skin what this means is that they get bigger the way I remember constriction and um dilation I just think a bow a constrict a snake or constrict around animal to try and digest it so wrap up really tight so it get smaller um and that's how remember that constriction is getting smaller whereas dilation the other one is getting bigger um hopefully that helps someone out um I am so thirsty so while more blood's being pumped out body we need we need to actually get rid of some of that not we don't want to get rid of it actually but we want to cool our body down so we redirect some blood toward our skin and so we have Vasa dilation toward our skin V constriction everywhere else this means more blood goes toward our skin it gets to our skin and then it undergoes um evaporation so it evaporates and this allows some of our um plasma to actually be lost as sweat and so this actually cools down our body this evaporation process cools down our body however it does result in a decreased blood volume so this is a cardiovascular cute response I mentioned before that cardiovascular cute responses refer to the heart and the vessels blood is the main fluid which travels in these vessels on the cardiovascular vessels and so this is why this is a cardiovascular CU response so decrease blood volume anything relating to blood is um a cardiovascular CU response okay this is kind of a hard one to explain so you've got something called an increased avo2 difference what does this stand for arterial vanual oxygen difference also known as av2 difference or A2 diff and this is a difference in the concentration of oxygen in the arterials which transport blood to the muscles compared to the venules which transport blood away from the muscles therefore it shows how much oxygen is actually being extracted from the blood and being used by the muscles when the body is performing physical activity av2 difference will increase as the muscle be demanding more oxygen and allows more ATP to be produced aerobically that's a good diagram but I'm going to draw one first I'm just conscious about time we are fine just hope freaking out about that here we have a heart I don't know why this chamber is a lot bigger than this one it's not a better hot look bounce it's not an anatomically God anatomically accurate heart or even a symbolically accurate looking one but anyway blood leaves your heart um if you know what vessel blood leaves your heart by it it be really happy if you don't Now's the Time to memorize it because it's important for your exam blood leaves your heart via arteries and arterials arteries and arterials and it goes off to capillaries where it will be diffused out into the working muscles so from the capillaries it enters the working muscles it returns back to your heart via veins and venules okay so blood leaves your heart oxygen blood leaves your heart and enters arteries and arterials it then goes up to the capillaries from the capillaries it then is diffused into the working muscles so that blood enters the working muscles or that oxygen from that blood enters the working muscles at the working muscles you also have um you know blood being use the oxygen extracted and you've got carbon dioxide kind of swapped here so carbon dioxide is substituted out and it enters um the carbon dioxide and oxygen kind of sort places oxygen leaves here enters the muscles carbon dioxide enters here and enters the veins and venil and then goes back to the heart okay so I'm going to say it again blood leaves the Heart by the arteries and arterials and returns back to the heart Val veins and manuals as I mentioned before got the three mechanisms of Venus return this glut muscle pump the respiratory pump and vtic constriction this is a hard thing to explain when your blood leaves your heart right here it's full of oxygen it is full of oxygen it's like yes lots of o2 here this is where you've got the swapping of oxygen so the oxygen leaves the blood stream here and enters the muscles here onwards there's no Oxygen left hopefully or a little bit of oxygen left because most of that oxygen is being extracted from the blood we don't want oxygen just travel around the body for no reason we want to extract it here to use it in our working muscles right we want to use up this oxygen in order to facilitate aerobic respiration in order to facilitate the use of the Aerobic System produce energy so we want to use that oxygen to rebuild ADP into ATP okay so it's really important that we want to get as much oxygen as possible so hopefully you know here we've got lots of oxygen here we've got most of oxygen extracted out so what is av2 difference this is if you measured a bunch of the blood here in the artery and a bunch of blood here in the vual and compared how much oxygen is there like you've got your blood which is fine but you want to see that there is a lot less oxygen here than there is here you'd expect you'd hopefully expect that a lot of that Oxygen's being extracted here therefore you've got barely any Oxygen left in the blood here does that makes sense so hopefully all of that Oxygen's been extracted here and you've only got a little bit or a tin tiny little bit or just even none left here and so you've got the most efficient extraction of oxygen here which means that a lot of oxygen has been extracted from the blood efficiently and taken to the working muscles where it will facilitate um uh it will facilitate uh respiration or aerobic energy production so hopefully that makes sense so and I'm going to use this diagram here we've got arterials and here we've got venal this is kind of like the other side of our diagram it's like looking at this part here artery and venue with the capillary in the middle and the muscles there so your arterials are oxygen rich blood they should have quite a lot of oxygen in them and you can see that this arterial here has 20 Ms of oxygen per 100 Ms of blood then it goes off and there's a capillary here or it diffuses into the working muscles okay so working muscles here then you've got the venules on the other side okay artery venel you can see in this manual you've actually got a BL oxygen concentration of 10 ms of oxygen per 100 Ms of blood so you can see you've actually got an arterial vual oxygen difference of 20 tiway 10 out of 100 m and this means we've actually got 10 ms of oxygen per 100 m of blood being extracted that's what your av2 difference is it's pretty much the difference in oxygen present in blood in the arteries as compared to the veins and venules okay so you're really just kind of looking at the difference in blood in these different vessels and the reason why we look at it is because it kind of tells you how efficient your body is at extracting the oxygen it needs in order to facilitate aerobic exercise okay hopefully that makes sense if it doesn't maybe put the question in the chat and I will get back to you on it um because I know it's quite a tricky concept and it is quite important to you to understand another cardiovascular acute response is blood redistribution so during physical activity blood is redirected from elsewhere in the body such as the organs towards the working muscles and this actually results in the working muscles receiving a higher percentage of the body's blood than they would during rest which results of more otion being delivered to the working muscles so when you're resting right now you might have just eating dinner maybe or breakfast or lunch or I'm not sure what time it is for you that you're watching this but you might have just eaten and so a lot of blood is being directed from all over your body and it's going to your stomach or your gut right and this is helping to facilitate the digestion of your food and so it's redirected there when you start physical activity however the blood is redirected from your gut or whatever and it's going toward your working muscles and so a lot more blood is going to your working muscles like in your legs or your arms to help you run and this is like an evolutionary trait or adaptation um so if you are suddenly being hunted by a line or something your body doesn't need to digest right this very minute that's like very low on the priority list what is high the priority list is getting lots of oxygen to your working muscles because it means that we'll have more oxygen going to the working muscles and therefore more Reliance on the aerobic Energy System as opposed to the anerobic Energy System therefore we've got less production of those metabolic fatigue byproducts such as hydrogen ions which were associated with lactic acid um which is produced um as a result of anerobic glycolysis and consequently you've got increased Reliance in the aeroic system and therefore for Less production of those fatiguing by products therefore more effective running um so that's why we do want that Aerobic System being most predominant supplier of energy so yeah um that blood is redirected from elsewhere in the body because your stomach doesn't need that oxygen right now but your muscles do and so your working muscles receive a high percentage of the body's blood in they wood during rest hopefully you can see this so in this diagram here at rest you know our muscles are getting quite a bit of oxygen and blood your heart's getting a bit Skin's getting a bit brain's getting quite a lot kidneys liver a lot this is kind of a dramatic diagram because your brain is obviously still getting quite a lot of oxygen and blood but um you can see that our muscles will suddenly take up like the majority of the blood um so more blood will be going toward your your muscles during physical activity because this this muscles the muscles need that oxygen at the moment to work aerobically so they'll be wanting to break down um carbohydrates aerobically and so remember that the breakdown of carbohydrate aerobically means you've got glycogen being breaken down to glucose and you've got glucose being breaken down to paric acid and then actually producing Hydro sorry not hydrogen um water carbon dioxide and heat as opposed to those hydrogen ions and lactic acid so uh make sure you understand that concept uh now we're to the last stretch of acute responses' got 25 minutes left which be okay so as I mentioned before our muscular acute responses are a type of acute response our previous ones ensured that more oxygen enters our body and bloodstream that was a respiratory one and our cardiovascular cute responses ensure that more blood and therefore more oxygen will travel to the working muscles I don't think I really emphasiz that enough so the cardiovascular one was really about blood traveling to our working muscles so we've got that Venus return because it means more blood can return back to the heart and then be um oxygenated before it goes back to the body so are three mechanisms of Venus return the scal muscle pump the vestic constriction and the uh respiratory pump these are all methods of ensuring that our blood returns back to our heart and therefore gets oxygenated um our other cardiovascular cute responses you increased heart rate means more Bloods pumped faster um increased left ventricle or blood leaving the vle that's a stroke volume that one is also a similar thing and then we've also got increased um uh cardiac output which is a produ a product of stroke volume and heart rate together um and then increased A2 difference this wasn't really about blood going to the working muscles exactly but more about the oxygen being extracted and what was the last one we just looked at blood redistribution more blood go into our working muscles as appears to our other organs in order to ensure that we've got the maximum amount of oxygen being extracted there and so we can have increased production of energy aerobically [Music] time so our muscular group sponsors are then responsible for ensuring that the extra oxygen is used to produce ATP okay this is a big one especially if you've never come across this phrase before um increased murder unit Recruitment and activation so murder units are the way in which muscles are actually controlled by the central nervous system so an increase in Murder unit recruitment simply means that more murder units are contracted and this results in a greater force being produced by the muscles the greater the force um required by a movement the more mer units will need to be recruited so when a Mur unit is activated will contract either maximally or not at all so this is known as the All or Nothing principle so the All or Nothing principle is a principle whereby it kind of talks about whether M units whe muscle contracts or not like it either contract maximally or it will contract not at all there is no like half-hearted contraction so when you have you know increased exercise intensity your body is going to undergo this acute response which is an increased Mar recruitment Activation so more Med will be recruited meaning a more contractile force is generated by the muscle you've got a greater muscle Force okay um that was a really bad definition pretty much increase muscular contraction it's a stronger contraction occur caring smaller slow twitch muscle faers are recruited first so um you've got many different types of muscle fibers some of them are small slow twitch type fibers the way I remember it is slow events like cross countries quiet slow event I would say um these require slow twitch fibers uh fast events like Sprints they they have fast twitch fibers so smaller slow twitch Master fibers are recruited first after this fast switch fibers type A and then the larger fast switch fibers type B are recruited recruited um the main thing I want you guys also to recognize with this area study is we've just covered like 15 different acute responses we'll need to know about four of them for each um system so like cardiovascular respiratory muscular if this is something which like doesn't really stick in your brain like you don't worry too much about it you need to pick your own for to remember for the exam I mean your SX maybe bit for the exam knowing about four of them should be fine and so this one doesn't really stick in your you can pick like four other types of muscular K responses and remember them instead because you need to be able to explain and discuss about four on your actual exam in case we carass you um also recall that like not all of these are really helping you exactly so our body doesn't increase in temperature to help us like that's not a benefit of exercise or like it's not a good arute response per se like your body just increases in temperature which is like it just happens it doesn't necessarily mean it's a good thing um but it's a side effect of what happens when you exercise and if you think about it if I think about myself going running right now you know the three main things I would say is increase respiratory rate increase heart rate and increase body temperature and so named an acute response from each of these three body systems okay anyway so increased temperature isn't necessarily a good thing what happens is that as a result of the increase in number of chemical reactions happening within the muscle we actually produce a lot more heat and so the heat escapes the muscles and the body through sweating and the flow of blood to the skin and this actually helps to exchange heat with the environment it can result in a decrease in body temperature okay so once again we've got vasid dilation of the blood vessels going toward the skin and vastic constriction of the blood vessels elsewhere we have the facilitation of sweating and um the loss of plasma in the blood through sweating to cool us down Um this can result in a decrease in body temperature so this increase in temperature isn't a good thing it just happens because we've got so many chemical reactions occurring within the muscles and thus this causes a larger production of heat another muscular acute response is the increased production of byproducts if the physical activity intensity is of a high standard and energy is being produced anerobic then byproducts be produced that may cause fatigue these include hydrogen ions which cause the muscle to become acidic and cause fatigue so I'm just going to like reass this I think it's been a while since I've said it um anerobic exercise or anerobic system such as the anerobic glycos system they cause metabolic fing B products so you've got the break down of glycogen into glucose into pyic acid this paric acid or Pate is then converted to lactic acid and then lactate lactate is associated with hydrogen ions H+ ions protons all the same thing nonetheless they actually interfere with the acidity of the muscles they kind of mess with the pH level of the muscles and can impede upon the muscular contractions happening there and this can cause fatigue which can then impede upon your performance and energy production okay so we really want to avoid this and so uh just generally if your activities of a high standard you're probably going to be overheating as a result you'll have to be using um vessa dilation and vess constriction to redirect the blood flow means less Bloods go into your working muscles therefore you've got to actually work um anerobic these at these muscles and so you're actually going to be using that anerobic system or those anerobic systems as such you're forced to produce these metabolic fatiguing byproducts so hydr ions as well as inorganic phosphate remember ATP breaking down ATP into ADP actually produces inorganic phosphate pi and this is actually a um a metabolic fitting byproduct also it's written as Pi like this so keep that in mind we was look at the production of adenosine diphosphate and this can also inhibit the sliding filament's ability to function at full capacity so your muscles will like slide across each other um got something called crossbridge formation you don't really look at this in VC but if you're interested look out masas and filaments or muscle contractions and how they occur there are lots of really good gifs gifs don't that word on the internet um but yeah this can impact upon the muscle ability to function full capacity and therefore reduce the velocity and force production of muscular contractions so that's why those byproducts are bad kind of inhibit um proper function of these muscles we've got decreased energy substrate levels so what are energy substrates it's pretty much just a fancy temp of fuels how much time we got left okay like 15 minutes we're fine um yeah so energy substrates is a fanasy ter F Fields so when energies produced Energy Fuels or substrates such as glucose triglycerides ATP and phosphocreatine will be used so these substrates are going to be consumed faster than they can be replenished and so as a result there'll be a decrease in energy substate levels at the muscles so obviously if you've if you're going running your body is using up those food fuels it's using up that glucose and so the amount of glycogen or glucose that was stored is going to decrease okay even triglycerides eventually so once you run two hours that glycogen store is probably completely like depleted and so your body's going to move on and start using fats or triglycerides and so as this time progresses your triglycerols are also going to deplenish um or just deplete ATP as well will be used up quite quickly and same with the phosphor creatine so all of these stores are going to start decreasing okay here we've got a really nice summary table of all of those acute responses we just talked about we've got the respiratory ones cardiovascular and muscular ones so remember respiratory rate is the amount of breaths taken per minute um you've going to increase respiratory rate when you start running because you want to take more breaths in order to allow more oxygen to enter your lungs and diffuse into the bloodstream you've got increased height of volume which is the amount of breath inhaled amount of sorry the volume of air inhaled per breath and so you take bigger breaths because you want to get more oxygen in per breath to maximize that efficiency there um and so obviously increasing amount of oxygen means more oxygen can be taken to the working muscles right the bloodstream therefore increased Reliance in the Aerobic System as opposed to anerobic system you've got increased ventilation remember that ventilation um is governed by the formula V equal t V * RR so it is a product of TI volume and respirator rate so increasing either of these will increase your ventilation and this is the amount of air I think inhaled a minute um something like that it's it's really just a sorry my brain is a bit tired I'm still recovering but it's pretty much a combination of respiratory and TI of volume put together and so increasing either of these will increase your ventilation you've got also increased pulmonary diffusion so pulmonary refers to lungs diffusion refers to exchange of gases and remember this is the exchange of gases across the Alvi you've got the swapping of oxygen from the lungs into the bloodstream so the oxygen can then travel um like it moves into the capillaries and it travels down to the working muscles where it's um able to be used or extracted for that aerobic respiration or aerobic energy production whereas the carbon duct that is swapped at the alol and you actually get that um carbon Dux it back into your lungs and exhale it out when you breathe out um in terms of cardiovascular acute responses you've got an increased heart rate heart rate is determined by uh beats of the heart per minute increase in the Beats of the heart per minute means more blood will get to the work of muscles faster and therefore you've got increased um efficiency using oxygen to facilitate your energy production we've also got increased Stoke volume so stroke volume is the amount of blood leaving the left ventricle per um beat and then cardic output Q is governed by Straight volume times heart R so increasing any of these will increase CTIC output also and this also aims to Endeavor aims to Endeavor um aims to get more blood going to the working muscles as needed you've got increased blood pressure which also is a similar thing increased blood pressure means more blood getting to the working muscles as you need it Li be decreased blood volume because you actually will have loss of some blood um through sweating the sweating process get the best dilation some Bloods lost its plasma so your blood volume will decrease it will be replenished eventually but just in like while exercising it will decrease you've got increased av2 difference so you've actually got increased extraction of oxygen occurring while exercising so you don't need so much oxygen being extracted right now while you are at rest but when you are exercising you do want to extract more oxygen because you do want to work more aerobically and there's kind of a higher need for you to work aerobically therefore Morin will be extracted from the blood um to your working muscles during exercise and this is a cardiovascular acute response you've also got increased Venus return this is the return of blood back the heart do recall this is really important that there are three main mechanisms of increasing ven return so they are the scal muscle pump so lifting your leg up constricting those muscles squishes those veins and forces the blood to go back to the heart those valves shutting behind it you've got the uh respiratory pump so when you breathe your diaphragm creates like a pressure gradient and this forces the blood to go back to the heart and the last one is vess constriction when the veins kind of constrict or stiffen up a bit and this forces the blood to go back to the heart once again you've also got increased blood redistribution and this is where the blood is redirected to the working muscles as opposed to other organs which perhaps are not as vely needing the blood at that very moment so things like the stomach don't need so much blood when you're being chased by something and so you've got more blood being D diverted to the working muscles in terms of muscular acute responses we've got increased Medi un recruitment so there's that All or Nothing principle whereby more units or contract our filaments are going to be recruited and they're going to contract and create a really forceful contraction or stronger muscular contraction you've got an increased temperature and this is because of the increased amount of reactions occurring in the muscles there you've got increased production of lactate and metabolic fing byproducts such as hydrogen ions just because of the increased temperature meaning increase rels on the anerobic glycosis system and it's satiated bioproducts and also you'll have decreased substrate levels because these substrates are being consumed they are food Fields so things like carbohydrates like glycogen or glucose stored or the free fatty acids and things they're going to be consumed in order to allow us to undergo there aerobic um systems producing the energy making process of those aerobic and anerobic systems that was a look okay just a bit of a summary there and then we're going to spend like the last 10 minutes kind of discussing study tips so TI p is um it's not the hardest subject exactly it's pretty content heavy so don't follow the Trap of treating as a blood subjects students do there's a lot to remember that most of it it's not too bad like do try and work through it I found a lot of it makes sense and it's quite logical and I think the best thing about PA as opposed to something like something I don't particularly understand real well like methods is that P is applicable to real life I couldn't really understand imaginary numbers I couldn't apply to my own life whereas with PE if I'm stuck on like a question relating to this content we just covered today I could be like okay what's an acute respiratory um mechanism to exercise right and I just think okay we're Spirit Tre when I start exercising my breathing rate is going to increase and it's kind of something I can see it's quite tangible so I kind of like that about PE and there also of sample questions as well and it's quite a chill subject for me like when I did it in high school we would have PE classes once a week and we'd go and play sport and it was like supposed to be a chance to kind of consolidate our learning but it was also kind of just fun so I think it's a good subject to really take the time to enjoy but also kind of like make sure you are studying hard too um anyway I think the end of it so I'm just going to go and discuss a few of my own study tips so um okay I've just done three years of uni I'm in my fourth year of uni now doing medicine it's pretty intensive and I think the worst thing about uni is you don't get as many practice exams as you do in high school so in high school you can go into the vard website and there are tons of practice exams on there so if I just um go to the vard webs it write it not open a new tab um you can go to vaa PE you can see how many times I've gone through it but you can download the study design you can also go back to the um there like glossery terms frequently asked questions this is a really good document so frequently asked questions is like a teacher guide and it kind of helps summarize um things which teachers often have trouble explaining so things like V A2 difference is quite a difficult concept V2 Max which I think we haven't talked about today but you might cover soon that's quite intense biomechanics is pretty intense um I think I did cover that previously in my like January series lectures um but there are many different topics which are quite heavy and they can be quite hard to understand and so if you're having a bit of trouble definitely look them up on the V car website because they actually have documents which are specifically designed to explain lactate inflection point or something like that um we just go back to past exams this is 2021 written exam where are the past exams are they why can I not see the exams oh here they go um yeah so you can see the past exams this is 2022 exam 2021 exam 2020 exam 2019 exam one two three four five so you've got five practice exams just relating to this study design I don't really have any of those at Uni like I think it's the worst part about uni is you don't get this these extra practice exams to do so um like the thing I highly recommend for high schoolers is definitely go back and do these past exams because they're there and you've actually got the vaa guide so literally the examiners who've written your exam have written exactly what they want to hear in response from you and if you start doing these exams like you'll start to see that they actually repeat the same kind of questions constantly so there'll be like problem questions willing to biome mechanics which come up every year just because people have quite a lot of trouble with them okay so it's really important that you do go back and look at these exams s got really paranoid that I wasn't recording anymore F eight minutes yes so you want to go back and do these past exams and really read the exam reports too so if you look at them they do provide quite comprehensive feedback and they go you know students who expose Express knowledge clearly and concisely connected that they did really well you know criticizing on analyzing was quite weak that kind of indicates the next year they'll probably give you more questions relating to this can also tell you what percentage of students got what right or wrong the ones where students didn't do so well at like maybe this one here um question eight is probably something that will come up the next year or this one here right so you really want to look at these problem areas and okay well people obviously didn't do very well here it's probably going to come up the next exam and so they give you more of a guide here and then once we get to the multiple choice so the short answer questions they're kind of a lot more detailed and they um really discuss what the examiners are looking for for each Mark they kind of display the marking criteria um the amount of students you got what Mark for the exam and yeah so I think it's really useful to go back at this look at this um we also have uh these other cost exam questions sorry like frequently asked questions referring to like lactate inflection point or other things s that okay it's just a bit slower reason every time I open up word my laptop takes like a whole like 3 minutes to load it I don't know why it's really slow um but yeah definitely take a look at these documents as well uh they kind of summarize those tricky Concepts make them a lot more digestible not just for PA by the way like I'd recommend looking at them for Bio or chemistry or other subjects you're having trouble with as well um often there's nfq dog that's a good one to go back and look at also um some other General things like how I studied I don't really know how many hours a week I study and I've kind of just lost count nowadays because I've got classes five days a week and I'll just have Anatomy for like an entire day um it really is more about prioritizing how you study like I will often spend an entire day studying and just absorb nothing just because I'm just so burnt out and overloaded by the sheer amount of content I'm doing right now so you really want to make sure that you are doing quality study um so maybe making flash cards and trying to actively learn things and recall it as opposed to just passively shoving into your bra brain and trying to hurt it stick it sticks um yeah so I don't really know how many hours a week of study I would probably like in high school there I would try and get all my study done at school like I would like eat during recess and kind of spend most of my time at the library studying during lunch which sounds a bit sad but it meant that I had my nights free like I was always working or doing search stuff with my friends or going away for the weekend stuff like that so I really wanted to keep my free time free like I had a lot of sports and piano and extracurricular stuff going on so trying to keep my afternoons and nights free um was kind of my priority so I would study during lunchtimes just to get it out of the way um to what exam season though I definitely did study a lot more see the frequently asked questions really useful document I recommend reading the entire thing like in its entirety it comes up with stuff that people don't understand as well um uh what was I saying oh exam stuff yeah so during exam season I definitely study a lot more people always asking how many exams I did I don't remember how many exactly for PA it wasn't as many as bio and for Bio I did 20 and I found that doing 20 really helped me to identify you kind of get used to the amount of questions with the type of questions that come up you can kind of like anticipate the answer like especially things like aute responses they're going to just start asking the same thing and the answers are going to get really repetitive so in doing 20 exams I think you kind of get really familiar with the exam style and the type of questions they're going to ask you and you kind of anticipate what the answer will be so I think doing 20 is a really good one like I got a 49 for Bio so and then like a 40 for PA so it's like a 10 Mark difference right um so yeah doing as many exams as you can is good I don't think anything more than 20 is really high yield but I think getting up to about 20 is a good um Target and so you can do these past ones on um the V website your teacher probably has a bunch of company exams as well what I would do is I would do an exam my first VI I felt totally out of my doubt and I was like wow what am I doing I feel completely lost and stuck I don't know what any of this is and so what I would do is I would do the exam I know i' suck the first time but that was whatever and I would go through and Mark it and any question I was kind of unsure about when I was doing the exam I'd kind of like make a mark next to it just make a note of it and then so when I'm correcting it any question I was unsure of or I got wrong even if I was unsure and I got it right I just going to make sure I write that down I would make a note of it in my notebook and write out like a full answer on why I got it wrong a description why I got it wrong um and just kind of an explanation and so I do that for every single question I got wrong and then I go back and review these like wrong answers and just make a note of them and just keep going back and reviewing that so I kind of had this entire book of like errors or unsure questions and I would just keep reviewing that until I fully understood the topics I'd also actually use the oos website so I don't know how active it is nowadays because I'm in uni now not in high school so I don't use VC stuff as much but um last time I checked the form it's still pretty active actually uh what I would do is particularly for Bio I know that one was really active but I think PA is a lot more active nowadays too I would just jump on there and put in a question I was stuck on and some like I had like an anonymous name and everything so people would know it was me but you can be as Anonymous as you want and yeah I'd put a question on that and some person would reply like someone who go really well fire and they would get back to me and it'd be like a really good explanation as to what I did wrong any you can obviously save all your questions for your teacher but like sometimes you might be spamming them especially if it's like 10:30 in school night you don't want to like for a weekend um it's a lot easier more convenient to put on the Forum so I would do that and put it on the forums so yeah someone would get back to me really quickly and I have my answer and I can make a note of that error with my notebook and just keep reviewing that and so I think it's a really effective way of studying doing lots of practice questions is really high yield making a note of all the RS all the errors you're making and then going back and reviewing that consistently I think that's the best way to study for VC and also doing as many practice exams as you want as you want um as you can so doing that 20 I think is a really good Target um I think we're kind of to the end of our session today you guys the probably putting in questions throughout the chat um while watching this so do let me know if any questions you have um but yeah that's really it from me today for p8 are we doing the bio one Aller so very look out for that one um and if you have any questions just send an email to Jmart or a notes put on the flums and yeah hopefully someone will get back to you soon so I hope you enjoyed that and thank you for coming and good luck VC you guys bye