Sedentary Lifestyle: Increase in technology and modern conveniences lead to more time spent in sedentary activities like watching TV, using computers, or playing video games.
Time Constraints: Busy lifestyles, with both parents working, limit time available for exercise.
Lack of Access to Safe Spaces: Some communities lack parks or other safe spaces for physical activities.
Cost Barriers: Expenses related to gym memberships and sports equipment can be prohibitive.
Health Conditions and Disabilities: Chronic health issues or disabilities limit mobility and physical activity.
Solutions
Community-wide initiatives, policy changes, infrastructural improvements, and individual behavior changes are needed to promote physical activity.
Metabolism: Anaerobic and Aerobic
Anaerobic Metabolism: Occurs without oxygen, primarily in the cytosol, producing energy rapidly but in limited amounts. Utilizes glucose, generating lactate as a byproduct.
Aerobic Metabolism: Occurs in the presence of oxygen, mainly within the mitochondria, slower but yields more energy. Utilizes carbs, fats, and proteins, producing CO2 and water as byproducts.
Importance of Respiratory and Cardiovascular Systems
Provide oxygen to muscles during physical activity.
At rest, systems supply sufficient oxygen for aerobic metabolism.
During exercise, heart rate and breathing increase to deliver more oxygen.
Energy Sources and Exercise
Initial Energy: Muscles use stored ATP and creatine phosphate, lasting a few seconds.
Anaerobic Metabolism: Provides rapid ATP from glucose for short duration.
Aerobic Metabolism: More efficient, producing ATP from glucose, fatty acids, or proteins during prolonged exercise.
Fuel Sources
Glucose: Comes from blood glucose, dietary carbs, liver, and muscle glycogen.
Fatty Acids: Main fuel during low to moderate intensity exercises.
Proteins: Used minimally unless dietary energy is insufficient or during prolonged exercise.
Exercise Intensity
Dictates fuel source for ATP production.
Low Intensity: Relies on aerobic metabolism.
High Intensity: Uses both anaerobic and aerobic metabolism.
Exercise Programs and Nutrition
Best exercise programs are those that individuals enjoy.
Nutrition for Athletic Performance
Energy intake supports bodily functions and influences nutrient intakes.
Athletes require specific energy needs based on activity level, duration, and intensity.
Carbohydrates: Fuel for brain and muscles.
Fats: Should make up 20-35% of calorie intake.
Proteins: Needed for muscle growth and repair (1.2 to 2.0 g/kg/day for athletes).
Protein in Diet
Accounts for about 5% of energy expenditure.
Importance of complete proteins (meat, dairy, eggs).
Vegetarians need to ensure complete protein intake.
Timing of protein intake influences muscle synthesis, ideally post-exercise and throughout the day.
Vitamins, Minerals, and Hydration
Vitamins and Minerals: Important for energy metabolism, oxygen delivery, and protection against oxidative damage.
Hydration: Critical for performance, involving cooling, oxygen transport, and waste removal.