Question

The following changes take place in an athlete’s body during a 100m race. Which change occurs first?
A. Increased availability of oxygen to muscles.
B. Increased breathing rate.
C. Increased carbon dioxide concentration in the blood
D. Increased production of carbon dioxide by muscles

Answer 1

Answer:

D. is the correct answer

Explanation:

during vigrous exercise availability of oxygen decrease so that cells starts anaerobic respiration .

Answer 2

The first change that happens when athletes run 100 metre races is an increase in carbon dioxide production by the muscle (option D).

• The heart pumps oxygenated blood to various regions of the body in a normal state, and carbon dioxide is produced as a by-product of respiration.
• The 100-meter sprint is a strenuous activity that raises the demand for oxygen in the muscles for energy production.
• As a result, when an athlete engages in such strenuous exercise, his or her muscles work harder, requiring more oxygen. The more oxygen absorbed by muscles, the more carbon dioxide produced as a by-product.
• The metabolic rate of the body cells is thus increased.