Which sequence correctly matches the effect on heart rate for warm-up, exercise, and cool-down?

• A. Warm-up increases heart rate; exercise increases heart rate; cool-down decreases heart rate.
• B. Warm-up decreases heart rate; exercise decreases heart rate; cool-down increases heart rate.
• C. Warm-up increases heart rate; exercise decreases heart rate; cool-down increases heart rate.
• D. Warm-up decreases heart rate; exercise increases heart rate; cool-down decreases heart rate.

Answer: (A)

During warm-up the body begins to require more blood flow as muscles prepare for activity, so heart rate rises from resting levels. As you start the main exercise, the demand for oxygen and removal of wastes increases again, pushing heart rate up further. In the cool-down, activity tapers off and the body returns toward resting needs, causing heart rate to decrease gradually. The sequence that reflects this pattern—heart rate increasing during warm-up, increasing again during exercise, then decreasing during cool-down—best matches how the body responds to these phases. The other options describe decreases during warm-up or exercise or an increase during cool-down, which doesn’t align with the way heart rate adapts to rising activity and subsequent recovery.