In the supine position after exercise, what happens to stroke volume and cardiac load?

In the supine position after exercise, what happens to stroke volume and cardiac load?

• A. Stroke volume decreases; cardiac load increases
• B. Stroke volume increases; cardiac load decreases
• C. Stroke volume unchanged; cardiac load unchanged
• D. Stroke volume decreases; cardiac load decreases

Answer: (B)

In the supine recovery state after exercise, venous return to the heart improves because gravity no longer pools blood in the legs. This extra venous return increases the end-diastolic volume, so the heart fills more each beat and, via the Frank-Starling mechanism, the stroke volume rises. At the same time, heart rate tends to drop during recovery as the autonomic balance shifts back toward parasympathetic dominance, and the immediate demands on the heart decrease. With fewer beats per minute and a more favorable loading condition, the overall cardiac workload decreases, even though each beat may push more blood due to the higher stroke volume. So, the combination is increased stroke volume with decreased cardiac load.

In the supine recovery state after exercise, venous return to the heart improves because gravity no longer pools blood in the legs. This extra venous return increases the end-diastolic volume, so the heart fills more each beat and, via the Frank-Starling mechanism, the stroke volume rises.

At the same time, heart rate tends to drop during recovery as the autonomic balance shifts back toward parasympathetic dominance, and the immediate demands on the heart decrease. With fewer beats per minute and a more favorable loading condition, the overall cardiac workload decreases, even though each beat may push more blood due to the higher stroke volume.

So, the combination is increased stroke volume with decreased cardiac load.