Which physiological response occurs during the first minute of exercise?

During the initial minute of exercise, the body undergoes a series of rapid physiological adaptations to meet the increased demands placed on it. One of the primary responses is an increase in both heart rate and stroke volume. As physical activity begins, the muscles require more oxygen and nutrients to sustain their increased workload. In response, the cardiovascular system reacts by elevating heart rate, which increases the number of times the heart pumps blood per minute.

Stroke volume, or the amount of blood pumped out of the heart with each beat, also rises during this time. This increased volume is crucial because it contributes to a higher cardiac output—the total volume of blood the heart pumps per minute—thus ensuring that more oxygenated blood can reach the working muscles quickly. This immediate response is vital for maintaining physical performance and ensuring that the body can keep up with the energy demands of the activity.

In contrast, decreased muscle oxygen demand and reduced blood flow to the skin do not accurately reflect the changes that occur at the onset of exercise. Instead, muscle oxygen demand increases significantly to support heightened activity, and while blood flow to certain non-essential areas may decline, overall blood flow to active muscles increases sharply. Stabilization of blood pressure can occur after the initial adjustments have settled, but during the