Question

Which of these methods would be most effective in allowing someone to precisely gauge the intensity level of his exercise?

Answer 1

the correct answer would be

Step-by-step explanation:

take his pulse.

Answer 2

You didn't really provide us with any possible list of methods. But to know how intense your exercise is, you would usually use the maximum amount of your heartbeats in a certain period to see how taxed your cardiovascular system is. This is also a good ballpark that tells you how intense your exercise is.