Question

which of the following is correct for an athlete who is exercising at a steady pace on flat terrain for a prolonged period of time? stroke volume gradually decreases and submaximal heart rate gradually increases cardiac output gradually decreases as they get used to the exercise load stroke volume and submaximal heart rate gradually decrease stroke volume and submaximal heart rate gradually increase

Explanation:

When an athlete exercises at a steady - pace on flat terrain for a prolonged period, the body adapts. Stroke volume increases initially to meet the oxygen demand. As the body gets more efficient, stroke volume can remain stable or even decrease slightly while the submaximal heart rate also decreases due to improved cardiovascular efficiency. Cardiac output (the product of stroke volume and heart rate) can be maintained with these adaptations.

Answer:

Stroke volume and submaximal heart rate gradually decrease