90 to 120 minutes
Glycogen is the storage form of glucose, the source of human energy derived from carbohydrates consumed through food. To assist in the storage process, molecules of glucose, a sugar composed of carbon, oxygen, and hydrogen atoms, are strung together to form glycogen, a complex molecule known as a polysaccharide. 1 When your body senses that you have extra glucose, it converts the glucose to glycogen by a process called glycogenesis. 2  The glycogen is stored in muscle and liver tissue. 3  As your blood glucose levels begin to run low, your body converts the glycogen back to glucose by a process called glycolysis. The skeletal muscles and the liver are the two chief storage facilities for glycogen. Approximately 1% of muscle mass is glycogen; between 8% and 10% of the liver's weight is stored glycogen. The skeletal muscles store two times as much glycogen as does the liver. Glycogen is the storage form of carbohydrates and is found in the liver and muscles. It is readily converted to glucose to be used as an immediate energy source, especially during vigorous or continuous exercise, such as a marathon. Glycogen is a storage of energy within the body, and glucose is the primary form of energy. So for example, if your body requires glucose to survive, when it has plentiful am … ounts. The capacity of your body to store muscle and liver glycogen, however, is limited to approximately 1,800 to 2,000 calories worth of energy, or enough fuel for 90 to 120 minutes of continuous, vigorous activity. Glycogen Structure. Glycogen is a polymer of glucose (up to 120,000 glucose residues) and is a primary carbohydrate storage form in animals. The polymer is composed of units of glucose linked alpha(1-4) with branches occurring alpha(1-6) approximately every 8-12 residues. Sometimes, the glucose in our body runs low, or even is depleted. When that happens, the body pulls the needed energy from glycogen stores in muscle and liver tissue, converting the glycogen into glucose. Exercise, illness, and some dietary habits, can cause the glycogen stores to be depleted more quickly.
http://www.faqs.org/sports-science/Fo-Ha/Glycogen-Depletion.html http://www.wikihow.com/Restore-Glycogen http://www.faqs.org/sports-science/Fo-Ha/Glycogen-Depletion.html http://www.livestrong.com/article/415921-what-happens-when-your-body-runs-out-of-glycogen-during-a-long-workout/ http://www.answers.com/Q/How_much_time_is_usually_needed_in_intense_activity_to_cause_depletion_of_glycogen_glucose http://www.humankinetics.com/excerpts/excerpts/the-bodyrsquos-fuel-sources http://oregonstate.edu/instruct/bb450/summer09/lecture/glycogennotes.html http://www.wikihow.com/Restore-Glycogen
How much time is usually needed in vigorous activity to cause depletion of glycogen reserves