the answer is A.) Heart rate
is a simple and practical method for monitoring the amount of work your heart is doing at any given time
The answer, I believe, is A. self esteem can fluctuate depending on circumstances
The principle of individualization is that no two people are the same. ... The principle of specificity is that exercising a certain body part or a particular skill primarily develops that part or skill.
<span>I would not have known this</span>