We humans are dependent on chemicals like water, air, sugars, starches, fats, proteins, as well as on small amounts of vitamins and minerals.
How you train is just as important as how much. Today's Olympic-class coaches design sophisticated programs for their athletes.
Olympic trainers take these systems into account. A long-distance runner should use aerobic metabolism for as much of her ATP as possible. To ensure this, she’ll be tested on a treadmill to measure her threshold of aerobic metabolism.
We need water, or H2O, to maintain our bodies in a fluid state. Water even gets involved in chemical reactions that occur in our stomachs, which break down foods containing sugars, starches, and proteins.