ATP is essential for muscle contraction (line 1).

Describe the roles of ATP in muscle contraction.

Calculate how long maximum exercise would last if ATP was not resynthesised (lines 3–4).

Answer ______________ s

Describe and explain how taking creatine supplements (lines 5–6) and 'carbohydrate loading' (lines 6–7) can improve performance of different types of muscle fibres during different types of exercise.

Suggest and explain how GLUT4 and CD36 transport proteins (lines 10–11) are beneficial during exercise.

An increase in muscle activity causes an increase in heart rate (lines 12–14).

Describe and explain how.