Exploring Muscle Fiber Types and Training

You ever seen an endurance athlete that just has like really long lanky style muscles? Have you ever seen a strength athlete that has a lot more of the bulky kind of faster looking muscles? Well, believe it or not, it's not just cosmetic. We actually have different kinds of muscle fibers within the body. And in this video, I want to help you understand what the type one muscle fibers are and what the type two muscle fibers are and how they were fueled and what they're predominantly used for. So let's dive right into what a type one muscle fiber is. See, type one is a slow twitch muscle. What that means is that it has a very low force output, but has a lot more in the way of endurance capabilities. So it has the ability to create energy for a long period of time. Now, slow twitch muscle fiber is usually very red in color if you were to look at it with a muscle biopsy test, simply because it has high amounts of what are called myoglobin, but also has a high amount of blood flow and a high amount of oxygen. You see, that slow twitch muscle utilizes the aerobic pathway for energy. It's not using carbs, it's using fats via beta oxidation. What does that mean? It means that the slow twitch muscles, the endurance muscles, use fat as a source of fuel. Which means that the fat has to combine with oxygen from the air that we breathe that gets carried in the blood in order to actually create energy. Hence why type 1 muscle fibers are much more red and have much more blood flow. Because they need the oxygen, they need the blood to actually create energy. Unlike a muscle that requires strictly carbohydrates in a chemical process to create energy. Now, because this oxygen reacts in the mitochondria to create energy, we also find that we have high levels of mitochondria in these slow twitch muscle fibers. And if you've done a low carb diet or a ketogenic diet or you've watched some of my videos, then you know that mitochondrial efficiency improves when you're in ketosis. Well, it would make sense that when you're on a low carb, high fat diet, you have a lot more endurance. You don't fatigue as much because the mitochondria can actually process it a lot easier. Okay, so now let's talk about type two fibers. It's as you start to increase intensity. of your workouts, you're going to start to recruit more of the type 2 muscle fibers that you have. But we have two different kinds of type 2. We have type 2a and type 2b. Type 2a is sort of the intermediary. It can do partially aerobic and partially anaerobic, which in my opinion is pretty darn cool. It has the ability to flip-flop back and forth. It has the ability to provide you with endurance function of the muscle, allowing you to say run middle distance like the 800 meter run or the one mile run. But it also has the ability to give you a lot of power. Now, Now, the caveat is it fatigues very fast. So it's a lot like a Type 1 in that it's a relatively low force output, but it can also go really, really high force output. But in both cases, it fatigues pretty fast. A good example of when you're using a Type 2a muscle fiber is when you're doing like an 80 to 90% workout, or maybe you're doing a CrossFit style workout where you're combining endurance with anaerobic, but you're not really pushing the envelope like you would be with powerlifting. That's where Type 2b comes in. Type 2B is strictly anaerobic. There's very little blood flow and there's not very red in color because it doesn't have high amounts of myoglobin and it doesn't get a lot of oxygen. It is strictly anaerobic, which means it's creating energy and creating force from carbohydrates. Now, a lot of you watching my channel probably follow a ketogenic or a fasting lifestyle and you're probably wondering, well, shoot, can I have strength and power without carbohydrates in this case? And the short answer is, well, your body's always going to find carbohydrates. It's always going to make them no matter what. So you always will have a little bit of force output with your type 2B. So you don't have to worry about that. So that leads me into the next part. Can you shift a muscle fiber to a different kind of muscle fiber, depending on how you're training or how you're eating? Well, yes and no. So there's actually some studies to back this up. In fact, there was a study that was published in the Journal of Strength and Conditioning Research that wanted to look at just this. They wanted to look at the effect of training and how it would change given muscle fiber types. Well, the short answer is what they found is that you can't shift from type 1 muscle fibers to type 2, but you can very easily shift from type 2a to type 2b depending on the type of training that you're doing. So what can we conclude from this though? Well, depending on how you're eating and what you're doing with your given lifestyle in terms of your workouts, you can dictate how your body is going to utilize these. If you're not in ketosis, it might be a good time to focus on recruiting a little bit more of the type 2b, allowing yourself to become stronger, allowing yourself to do a little bit more in the way of power movements. But then, when you go into more of a ketogenic lifestyle, then you want to focus more on your type 2A, meaning doing the intermediary stuff. You don't have to go hardcore just into endurance work, but you can go into a little bit more 80% workouts where you're doing kind of halfway between anaerobic work and halfway between aerobic work. It's a lot of what I do now. So focusing on the higher repetition range, but still keeping cardio involved too. So you're leveraging the power that you get from a ketogenic lifestyle or a low carb diet, but still also... keeping that type 2b portion a little bit alive by still incorporating the strength work. What's interesting, what that study had found, you don't ever increase the amount of muscle fibers that you have, but you do increase their size. So for example, if we are born with 50% slow twitch and 50% fast twitch, you're never going to be able to make yourself have more fast twitch, but you are going to allow those fast twitch muscles to become bigger. You're not going to have hyperplasia where you're actually creating more muscle fibers. So, for example, some people are born with a little bit more of one another. So it depends on what kind of athlete you are. Some very gifted endurance athletes might be born with something more like 70% slow twitch and 30% fast twitch. It doesn't mean that they can convert that extra fast twitch that they have at 30% over to slow twitch or vice versa. They can't take 20% of their slow twitch and make them more fast twitch. But they can shrink or enlarge a given muscle fiber type depending on how they train. So, although it's not the answer that you're probably looking for, you can't go from an endurance athlete to being a perfect strength athlete, you can find that middle ground by leveraging the power of a Type 2a muscle fiber, which means train in that zone where you're doing a little bit of both. A little bit of strength training, a little bit of endurance work. As always, keep it locked in here on my channel. If you have ideas for future videos, you know where to put them down below. See you soon.

So let's dive right into what a type one muscle fiber is. See, type one is a slow twitch muscle. What that means is that it has a very low force output, but has a lot more in the way of endurance capabilities.

So it has the ability to create energy for a long period of time. Now, slow twitch muscle fiber is usually very red in color if you were to look at it with a muscle biopsy test, simply because it has high amounts of what are called myoglobin, but also has a high amount of blood flow and a high amount of oxygen. You see, that slow twitch muscle utilizes the aerobic pathway for energy. It's not using carbs, it's using fats via beta oxidation. What does that mean?

It means that the slow twitch muscles, the endurance muscles, use fat as a source of fuel. Which means that the fat has to combine with oxygen from the air that we breathe that gets carried in the blood in order to actually create energy. Hence why type 1 muscle fibers are much more red and have much more blood flow. Because they need the oxygen, they need the blood to actually create energy.

Unlike a muscle that requires strictly carbohydrates in a chemical process to create energy. Now, because this oxygen reacts in the mitochondria to create energy, we also find that we have high levels of mitochondria in these slow twitch muscle fibers. And if you've done a low carb diet or a ketogenic diet or you've watched some of my videos, then you know that mitochondrial efficiency improves when you're in ketosis.

Well, it would make sense that when you're on a low carb, high fat diet, you have a lot more endurance. You don't fatigue as much because the mitochondria can actually process it a lot easier. Okay, so now let's talk about type two fibers.

It's as you start to increase intensity. of your workouts, you're going to start to recruit more of the type 2 muscle fibers that you have. But we have two different kinds of type 2. We have type 2a and type 2b.

Type 2a is sort of the intermediary. It can do partially aerobic and partially anaerobic, which in my opinion is pretty darn cool. It has the ability to flip-flop back and forth.

It has the ability to provide you with endurance function of the muscle, allowing you to say run middle distance like the 800 meter run or the one mile run. But it also has the ability to give you a lot of power. Now, Now, the caveat is it fatigues very fast.

So it's a lot like a Type 1 in that it's a relatively low force output, but it can also go really, really high force output. But in both cases, it fatigues pretty fast. A good example of when you're using a Type 2a muscle fiber is when you're doing like an 80 to 90% workout, or maybe you're doing a CrossFit style workout where you're combining endurance with anaerobic, but you're not really pushing the envelope like you would be with powerlifting. That's where Type 2b comes in.

Type 2B is strictly anaerobic. There's very little blood flow and there's not very red in color because it doesn't have high amounts of myoglobin and it doesn't get a lot of oxygen. It is strictly anaerobic, which means it's creating energy and creating force from carbohydrates. Now, a lot of you watching my channel probably follow a ketogenic or a fasting lifestyle and you're probably wondering, well, shoot, can I have strength and power without carbohydrates in this case? And the short answer is, well, your body's always going to find carbohydrates.

It's always going to make them no matter what. So you always will have a little bit of force output with your type 2B. So you don't have to worry about that. So that leads me into the next part.

Can you shift a muscle fiber to a different kind of muscle fiber, depending on how you're training or how you're eating? Well, yes and no. So there's actually some studies to back this up. In fact, there was a study that was published in the Journal of Strength and Conditioning Research that wanted to look at just this. They wanted to look at the effect of training and how it would change given muscle fiber types.

Well, the short answer is what they found is that you can't shift from type 1 muscle fibers to type 2, but you can very easily shift from type 2a to type 2b depending on the type of training that you're doing. So what can we conclude from this though? Well, depending on how you're eating and what you're doing with your given lifestyle in terms of your workouts, you can dictate how your body is going to utilize these.

If you're not in ketosis, it might be a good time to focus on recruiting a little bit more of the type 2b, allowing yourself to become stronger, allowing yourself to do a little bit more in the way of power movements. But then, when you go into more of a ketogenic lifestyle, then you want to focus more on your type 2A, meaning doing the intermediary stuff. You don't have to go hardcore just into endurance work, but you can go into a little bit more 80% workouts where you're doing kind of halfway between anaerobic work and halfway between aerobic work. It's a lot of what I do now.

So focusing on the higher repetition range, but still keeping cardio involved too. So you're leveraging the power that you get from a ketogenic lifestyle or a low carb diet, but still also... keeping that type 2b portion a little bit alive by still incorporating the strength work. What's interesting, what that study had found, you don't ever increase the amount of muscle fibers that you have, but you do increase their size. So for example, if we are born with 50% slow twitch and 50% fast twitch, you're never going to be able to make yourself have more fast twitch, but you are going to allow those fast twitch muscles to become bigger.

You're not going to have hyperplasia where you're actually creating more muscle fibers. So, for example, some people are born with a little bit more of one another. So it depends on what kind of athlete you are. Some very gifted endurance athletes might be born with something more like 70% slow twitch and 30% fast twitch. It doesn't mean that they can convert that extra fast twitch that they have at 30% over to slow twitch or vice versa.

They can't take 20% of their slow twitch and make them more fast twitch. But they can shrink or enlarge a given muscle fiber type depending on how they train. So, although it's not the answer that you're probably looking for, you can't go from an endurance athlete to being a perfect strength athlete, you can find that middle ground by leveraging the power of a Type 2a muscle fiber, which means train in that zone where you're doing a little bit of both.

A little bit of strength training, a little bit of endurance work. As always, keep it locked in here on my channel. If you have ideas for future videos, you know where to put them down below.

See you soon.

Transcript for:Exploring Muscle Fiber Types and Training

Transcript for:
Exploring Muscle Fiber Types and Training