The Physiology of Training Practice Test

Endurance training tends to make the cardiovascular system more efficient, so the brain doesn’t need to send as much anticipatory (feed-forward) input to the heart and blood vessels to meet the demands of submaximal exercise. This feed-forward signal originates from higher brain centers and modulates the cardiovascular control center, which governs heart rate and vascular tone. With training, adaptations such as a larger stroke volume and better autonomic balance (more vagal tone at rest and during submaximal effort) mean the heart can handle the same workload with less central command. That reduced drive specifically targets the cardiovascular control center, lowering heart rate and limiting unnecessary sympathetic output at submaximal intensities. The other centers listed—respiratory, thermoregulatory, and digestive—do not receive the primary training-induced decrease in feed-forward signaling in this submaximal context.