tag:blogger.com,1999:blog-8126172562542360329.post-5374491813544492522007-05-21T11:57:00.000-05:002007-05-21T13:13:10.109-05:00At rest and during normal activities, fats provide 80-90% of the energy source; carbohydrates provide 5-18%; and protein provides 2-5%.<br /><br />During low to moderate intensity aerobic activity (long duration, steady speed, also known as endurance exercise), fat is a significant energy source.<br /><br />Exercise above 60-65% of maximal oxygen uptake, carbohydrate is needed as a fuel source.<br /><br />During prolonged exercise, there is a reliance on carbohydrate to provide pyruvate for continued fat oxidation.<br /><br />Muscle glycogen (the storage form of carbohydrate in the muscle) is depleted in 2-3 hours of continuous exercise at 60-80% of oxygen uptake.Elizabethhttp://www.blogger.com/profile/07953485487306202579noreply@blogger.com