Assessment and Qualifications Alliance (AQA) GCSE PE Paper 2 Practice

Proteins are essential for muscle repair and growth because they provide the building blocks known as amino acids, which are crucial for the body's recovery processes after exercise or injury. When you engage in physical activities, especially strength training, small tears occur in the muscle fibers. Consuming protein after these workouts helps to repair these fibers, leading to muscle growth and enhanced strength over time.

In addition to repairs, proteins are integral in the development of new muscle tissue, allowing for increases in muscle mass when paired with proper training. While carbohydrates and fats serve important roles in providing energy for workouts and overall body functions, and vitamins are vital for various biochemical processes, they do not directly contribute to muscle repair and growth in the same way that proteins do.