Answer:
The respiratory rates of the runners returned to the resting rate 3 minutes post-exercise.
Step-by-step explanation:
1.) The runners had an overall lower resting respiratory rate than the non-runners.
2.) Although both experienced an elevation in respiratory rate during exercise, the non-runners' respiratory rates had a larger increase.
3.) In the 3 minutes post-exercise, the runners were able to return to resting respiratory rate, while the non-runners were not.
4.) The correct answer is: The respiratory rates of the runners returned to the resting rate 3 minutes post-exercise.