I haven't seen anything specifically addressing the use of caffeine in athletics lately, so I figured I'd share something I found while reading the fourth edition of Exercise Testing and Prescription, subtitled A Health-Related Approach, written by David C. Nieman, DrPH, FACSM. This is a textbook utilized for those studying Exercise Physiology. This is by no means a well kept secret, but worth being offered as a refresher or informative to those who have yet to discover.
Use of Caffeine to Improve Performance in Long Endurance Events
Despite the widespread use of caffeinated beverages by Americans, a growing number of studies are providing evidence that this drug is not as benign as once thought. Daily caffeine intake has been related to osteoporosis, birth defects, and sleep interference, and this drug exhibits the features of a typical psychoactive substance leading to dependance. One in three Americans consumes approximately 200 mg caffeine (equivalent to 1-2 cups of coffee) per day. Caffeine is an alkaloid present in more than 60 plant species. Peak plasma levels after ingestion occur within 15-45 minutes, with a plasma half-life ranging from 2.5 to 7.5 hours. The metabolism by the liver, storage, and clearance rate of caffeine may vary greatly between acute and chronic users.
There is growing evidence that caffeine ingestion (3-9 mg/kg body weight) prior to exercise and short-term intense exercise lasting about 5 minutes. Caffeine taken 1 hour prior to exercise will enhance endurance performance 10-30%, although individual responses can vary widely.
Caffeine tends to elevate catecholamines (dopamine, adrenaline, noradrenaline, and so forth) and free fatty acids in the blood. When exercising muscles are presented with elevated levels of free fatty acids at the beginning of exercise, the muscles will increase their utilization of fat, sparing the muscle glycogen, resulting in improved endurance. Cafeine also appears to have a "neural" effect, decreasing the perception of effort.
The American College of Sports Medicine does not recommend the use of caffeine for enhan***ent of perfomance. The International Olympic Committee has banned caffeine present in urine at levels greater than 12 mcg/ml urine. It takes about 6 cups of brewed coffee (at 100-mg caffeine per cup) to reach this level. Three tablets of Vivarin or six tablets of NoDoz would have the same effect as 6 cups of coffee. The ergogenic effects of caffeine are present with urinary caffeine levels that are below the limit of 12 mcg/ml, raising serious ethical issues regarding the use of cadffeine by athletes. Note that since the 2000 Olympics, caffeine has been banned by the International Olympic Committee. The level that is banned is approximately 8 cups of coffee. If the IOC found that much caffeine in your urine, they would assume that you are trying to gain a competitive advantage.
Comments italicized are my additions, and comments in bold are those which I found to be of particular relevance. Have any of you experimented with coffee while trying to cut fat or enhance endurance athletics?
Reply With Quote
