During heavy exercise, we get cramps in the legs due to the accumulation ofA. Carbon dioxideB. Lactic acidC. AlcoholD. Water

During heavy exercise, the cramps in the legs are primarily caused by the accumulation of lactic acid. Therefore, the correct answer is B. Lactic acid.

Lactic acid is produced as a byproduct of anaerobic metabolism, which occurs when there is an insufficient supply of oxygen to meet the energy demands of the muscles during intense exercise. As oxygen becomes limited, the body relies more on anaerobic processes to generate energy. This leads to the breakdown of glucose without oxygen, resulting in the production of lactic acid.

The accumulation of lactic acid in the muscles can contribute to the sensation of muscle fatigue and the development of cramps. It is important to note that dehydration and electrolyte imbalances can also play a role in muscle cramping during exercise. Therefore, maintaining proper hydration and electrolyte balance is crucial to prevent cramps.