A 23-year-old man undergoes exercise physiology testing at sea level. He jogs on a treadmill to achieve a moderate-intensity physical activity level based on a target heart rate of 50%-70% of his estimated maximum heart rate. An increase in which of the following is expected at the peak of his exertion?

Question

A 23-year-old man undergoes exercise physiology testing at sea level.  He jogs on a treadmill to achieve a moderate-intensity physical activity level based on a target heart rate of 50%-70% of his estimated maximum heart rate.  An increase in which of the following is expected at the peak of his exertion?

Quizplus · Accepted Answer

Eductional Objective: During physical exercise, there is increased skeletal muscle CO₂ production that increases the CO₂ content of venous blood. Arterial O₂ and CO₂ content remains constant via increases in alveolar ventilation and gas exchange efficiency. Venous O₂ content remains constant or is decreased due to increased O₂ extraction by the tissues that matches or exceeds the rate of oxygen delivery (ie, O₂ consumption during exercise is limited by cardiac output).

A 23-Year-Old Man Undergoes Exercise Physiology Testing at Sea Level