Training Dictionary
Glycolysis
Definition: Glycolysis is the metabolic breakdown of glucose into pyruvate to create ATP for muscle contractions and NADH to fuel energy production utilizing oxidative phosphorylation.
Glycolysis is used in moderate to heavy activity. Glycolysis uses either muscle glycogen or blood glucose which is produced from the breakdown of ingested food and the breakdown of glycogen stored in the liver.1
Simplified Biochemical Reaction:
Glucose + NAD+ + Pi + ADP → pyruvate + NADH + ATP 2
(don't worry, I'll explain these terms in the near future)
Effects of Exercise
With extensive aerobic exercise, the body is able burn a greater percentage of fat for energy and spare the breakdown of glycogen. With more muscle glycogen spared available, it is possible to sustain light to moderate activity.3
With training, It is also possible to increase the rate at which glycolysis takes place. This will allow energy to burn quicker, resulting in an increase of power output.4
Important Details
Glycolysis uses either muscle glycogen or blood glucose which is produced from the breakdown of ingested food and the breakdown of glycogen stored in the liver. When glycogen diminishes you will "hit the wall" and have difficulty exercising.
Sources:
1 McArdle, Katch, F. I., & V. L. Katch, 2001. Exercise Physiology: Energy, Nutrition, and Human Performance. 5th Edition. Lippincott Williams & Wilkins, Philadelphia: 141-143 pp.
2 Nelson D. L., M. M. Cox 2005. Principles of Biochemistry. 4th Edition. W. H. Freeman & Company, New York: 522-525 pp.
3 American College of Sports Medicine, 2006. ACSM's Resource Manual for Guidelines for Exercise Testing and Prescription. 5th Edition. Lippincott Williams & Wilkens, Philadelphia: 65 p.
4Nelson D. L., M. M. Cox 2005. Principles of Biochemistry. 4th Edition. W. H. Freeman & Company, New York: 593-594 pp.
