How do Peter's physiological responses compare to Rob's during aerobic exercise?

The physiological responses during aerobic exercise are critical in understanding how the body adapts to physical activity. When comparing Peter's and Rob's responses, a lower heart rate along with a greater stroke volume indicates a more efficient cardiovascular system. Individuals who are more fit typically exhibit a lower resting heart rate and can pump more blood with each heartbeat, which translates to greater stroke volume.

A lower heart rate suggests that Peter's heart doesn't need to work as hard to supply oxygen to his muscles during exercise, which is often the case for trained athletes or individuals with higher aerobic capacity. At the same time, a greater stroke volume means that his heart is able to eject a larger volume of blood with each contraction, delivering more oxygen to the working muscles efficiently.

This combination of physiological factors suggests a higher level of cardiovascular fitness and endurance in Peter compared to Rob. The opposite options indicate variations that would imply less efficiency or different responses to aerobic activity, which do not align with the implications of an improved fitness level typically observed in trained individuals. Thus, the assessment of Peter's responses as exhibiting a lower heart rate and a greater stroke volume accurately reflects the adaptations associated with regular aerobic exercise training.