Which one of the following choices is a waste product generated by the muscles during exercise?
a. oxygen
b. amino acids
c. lactic acid
d. nitrogenwhich one of the following choices is a waste product generated by the muscles during exercise?
a. oxygen
b. amino acids
c. lactic acid
d. nitrogen

During exercise, we undergo respiration. Therefore, we need oxygen and release carbon dioxide and water as waste products. When exercise become vigorous, we only run on anaerobic respiration with little oxygen, then lactic acid becomes a waste product instead of carbon dioxide and water. This occurs due to incomplete breakdown of glucose.

Best answer is C. lactic acid.