When it is broken down, it releases a total of 100 units (i. e. , change in e = 100), but only about 40 units is usable energy. The other 60 units become non-useable energy (i. e. , heat): e total = useable + non-useable e, adenosine triphosphate (atp) holds energy, composed of, adenine base, ribose sugar, 3 x phosphate. Exercise metabolism general overview: the focus of this chapter is metabolism with respect to exercise, major fuels, phosphocreatine, carbohydrates, glycogen (storage form, glucose (useable form, lipids, triglycerides (storage form) Responsible for about 95% of energy: fatty acids (useable form, proteins, amino acids (useable form, key tissues (more specific than before): Refer to summary chart at the end of this document. P: creatine, 1 p group, atp, 3 p groups, adp, 2 p groups. Creatine supplements: proposal, t ke cre tine, cr , in order to (cid:323) our stor ge of cr, at rest, these cr can be converted to pcr using extra.