Regular participation in moderate-to-high intensity activity over time is most likely to produce which change in a physiological measurement?

• A. increased resting heart rate.
• B. decreased resting heart rate.
• C. increased maximal heart rate.
• D. no change in blood pressure at rest.

Answer: (B)

Regular aerobic training makes the heart more efficient, increasing the amount of blood pumped with each beat (stroke volume). With a larger stroke volume, the same amount of blood can be circulated with fewer beats per minute, so the resting heart rate decreases. This reflects better cardiac efficiency and greater parasympathetic (vagal) influence at rest. Maximal heart rate is not typically raised by training and tends to be governed more by age, while resting blood pressure can drop slightly but is not the primary, consistent change described here.