Pulse rate drops after exercise stops

Steps:

• Identify the rising phase of the graph as the pedaling period, where pulse rate increases due to exertion.
• Locate the peak or plateau, indicating sustained pedaling.
• Find the point where the pulse rate begins a sharp decline, signaling the end of physical activity.
• Confirm the decline aligns with resting, as heart rate returns to baseline without ongoing effort.

Why B is correct:

• Point B marks the onset of decreasing pulse rate, consistent with the physiological response where heart rate falls rapidly after exercise cessation due to reduced oxygen demand.

Why the others are wrong:

• A: Occurs during the rising pulse rate, indicating ongoing pedaling.
• C: Lies in the declining phase after stopping, not the stop point itself.
• D: Represents full rest with stabilized low rate, post-decline.

Final answer: B