ATP PRODUCTION & THE ENERGY SYSTEMS WORKSHEET
Chemical Energy enters the body in the food we eat through the macronutrients: carbohydrates
(glucose), fats (fatty acids), & proteins (amino acids).
Chemical Energy is converted into ATP (the body’s “energy currency”) through 3 distinct energy
systems. These energy systems use ATP to generate muscle contractions and allow the body to
complete the many processes necessary to keep the human body alive (ex. maintain homeostasis and
allow for our metabolism to sustain life through the billions of cells in our body).
Carbohydrates provide approximately 50% of the ATP at rest, however, during sub-maximal to maximal
muscle contraction carbohydrates provide almost 100% of the ATP. We store approximately 2000
calories of carbohydrates (as glycogen) in muscles or the liver, enough for a 30 km run.
Fats provide approximately 50% of the ATP at rest. Fats must be broken down (through the digestive