Training for the Uphill Athlete: A Manual for Mountain Runners and Ski Mountaineers

Think of metabolism as a miniature ATP recycling plant in the muscle cells. After ATP is broken apart to extract the energy needed for muscle contraction, then the metabolic recycling plant using the energy from food reassembles the ATP molecules so the whole process can keep going.

Metabolism is the term for the biochemical process of breaking down the molecular bonds in the fats and sugars for the energy needed to assemble the molecule ATP.

Adenosine Triphosphate is a short-term energy storage molecule used by every cell in your body.

Most importantly for athletes, ATP’s energy is used to power muscular contractions.