Question

All intensities above _________% of VO2 max, the contribution of anaerobic metabolism increases, resulting in a curvilinear increase in HR.

A) 50%
B) 60%
C) 70%
D) 80%

Answer 1

The correct answer to the question regarding VO2 max and anaerobic metabolism is D) 80%. Above this level of exercise intensity, anaerobic metabolism's contribution increases, which leads to a curvilinear increase in heart rate.

Step-by-step explanation:

The question relates to the physiological response during exercise, specifically in relation to the contribution of anaerobic metabolism at different intensities of VO2 max. Anaerobic metabolism becomes more significant when the exercise intensity surpasses a certain threshold of VO2 max. This results in a curvilinear increase in heart rate (HR). The correct answer is D) 80%. Therefore, all intensities above 80% of VO2 max, the contribution of anaerobic metabolism increases.

This is because at high exercise intensities, aerobic metabolism can no longer meet the energy demands of the muscles, and as a result, the muscles resort to anaerobic respiration for short-term, intense activities such as hurdling.In the context of the oxygen-hemoglobin dissociation curve, as the curve levels off around a partial pressure of 60 mmHg, it indicates that hemoglobin is reaching a high level of saturation with oxygen. This S-shaped curve demonstrates the allosteric properties of hemoglobin and its affinity for oxygen under various partial pressures.