Usain St. Leo Bolt, World Champion
Usain St. Leo Bolt, a Jamaican sprinter who competed in the 2012 London Olympics, is widely known as the fastest man ever. Bolt is the first man in history to hold both the world records for the 100 meter and 200 meter sprint. He earned gold medals in both of these events at the 2008 and 2012 Olympics (Usain Bolt 2012). When sprinting, Bolt’s body must produce enough energy to run 100 meters in 9.63 seconds. There are amazing processes going on simultaneously within this runner’s body that are allowing this all to happen.
The Origin of Energy
Metabolic processes begin long before an athlete competes. In fact, the precursors to these processes begin at the dinner table. Energy begins in the form of a healthy meal consisting of carbohydrates, fatty acids, and amino acids. These “fuel” molecules are then metabolized into substances such as glucose, pyruvate, lactate, and the aforementioned acetyl-CoA.
The end product of these metabolic processes is a very important molecule called adenosine triphosphate (ATP). ATP is the molecule that supplies our body with the necessary energy to perform. The cells that make up our body all use ATP to perform many necessary functions such as cell signaling (Bell et al. 2003), transport of molecules in and out of cells (Skou 1965), muscle contraction (Adelstein and Eisenberg 1980), and even for the synthesis of more ATP through our metabolism (Champe and Harvey 1987, Campbell et al. 2005). Through cell signaling, ATP allows our central and peripheral nervous system to function properly (Bell et al. 2003), it allows actin and myosin crossbridges in our muscles to function so that we can flex and contract muscles (Adelstein and Eisenberg 1980), allowing us to move and perform. In our metabolism, ATP is used to allow glycolysis to continue, which in turn produces more ATP (Champe and Harvey 1987, Campbell et al. 2005). When our body has low levels of ATP, it knows when to produce more and will increase the rate of glycolysis and the citric acid cycle accordingly.
Glycolysis literally translated means to split sugar (Glucose—sugar, lyse—to split). Glycolysis can be aerobic when we have sufficient oxygen, or anaerobic when the oxygen in our system is low. Virtually all sugars can be converted to glucose which is free to diffuse in and out of the cells that make up the different tissues of our body. Glycolysis is a process that ends up in a net formation of two ATP molecules per glucose molecule.
Anaerobic glycolysis takes place without oxygen and is the way our metabolism supplements the demand for short, intense bursts of energy. Events lasting approximately 10 seconds or somewhat longer (e.g. 100-m run) utilize anaerobic glycolysis for energy in ATP production (Knuttgen and Komi 2003). This can only be sustained for short periods of time (Knuttgen and Komi 2003). Lactic acid is produced during anaerobic glycolysis and is responsible for the burning sensation sometimes felt in muscle fibers.
Aerobic Glycolysis and The Citric Acid Cycle
When there is adequate oxygen in the body, aerobic glycolysis takes place and is coupled to the citric acid cycle. The citric acid cycle yields much more energy than glycolysis alone. If we add all of the energy yielding products of the breakdown of one glucose molecule, we can obtain 15-17 times more ATP through the breakdown of one glucose molecule.
By: Josh Sewell, University of Utah
Joshua Sewell graduated from Brigham Young University-Idaho with a Bachelor’s of Science in chemistry and a minor in biology. He is fascinated by biochemistry and the processes that make the body work. Josh is currently a graduate student working on a Ph.D. in chemical engineering where he is focused on microbially enhanced coalbed methane recovery and applications. Outside of the lab, Josh enjoys spending time with his wife, Sara, and his two daughters, Oakley and Zoe.
Adelstein, R. S., & E. Eisenberg. 1980. Regulation and Kinetics of the Actin-Myosin-ATP Interaction. Annual Review of Biochemistry 49: 921-56.
Bell, P. D., J.Y. Lapointe, R. Sabirov, S. Hayashi, J. Peti-Peterdi, K. Manabe . 2003. Macula densa cell signaling involves ATP release through a maxi anion channel. Proceedings of the National Academy of Sciences of the United States of America 100 (7): 4322-27.
Ericinska, M., & F. Dagani. 1990. Relationships between the neuronal sodium/potassium pump and energy metabolism. Effects of K+, Na+, and adenosine triphosphate in isolated brain synaptosomes. The Journal of General Physiology 95 (4): 591-616.
Knuttgen, H. G., & P.V. Komi. 2003. Basic Considerations for Exercise. In P. V. Komi (Ed.). Strength and Power in Sport (Vol. 3). Blackwell Science, Malden, Massachusetts, USA.
Champe, P., & R.A. Harvey. 1987. Lippincott’s Illustrated Reviews: Biochemistry. J.B. Lippincott Company, Philadelphia, Pennsylvania, USA.
Campbell, P. A. Smith, & T. Peters. 2005. Biochemistry Illustrated, Biochemistry and molecular biology in the post-genomic era (Fifth ed.). Elsevier Churchill Livingstone, Edinburgh, Scotland.
Skou, J. 1965. Enzymatic basis for active transport Na+ and K+ across cell membrane. Physiological Reviews 45 (3): 596-618.
Usain Bolt. (2012, August). Usain Bolt. Retrieved from http://usainbolt.com/bio/.com/bio/
Articles by Josh Sewell.