Suggest and explain why a sprinter can use mainly anaerobic respiration during the race, while a marathon runner needs to use aerobic respiration.

Sprinter hold their breath while marathon runner didn't.

Explanation:

A sprinter can use mainly anaerobic respiration during  the race because a sprinters hold their breath during a race so due to lack of oxygen it takes energy from anaerobic respiration, while a marathon runner needs to use aerobic respiration because he use oxygen during their race and by using oxygen aerobic respiration is executed. So we can conclude that sprinters use anaerobic respiration while marathon runner use aerobic respiration during running.

b.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.