3. What is a nutrient and give an example of one and what it does.

a substance that provides nourishment essential for growth and the maintenance of life.     Examples include proteins, fats, carbohydrates, vitamins, and minerals.

Explanation:

These are the dictionary definitions so i would recomend paraphrasing. Hope this helps

the more fit you are, the faster the recovery. your heart rate drops most sharply in the first minute after you stop exercising; it should then fall about 20 beats a minute—a drop of less than 12 beats a minute is considered abnormal. this “recovery heart rate” is measured as part of an exercise stress test.