Caffiene

Caffeine is a central nervous system stimulant: it stimulates the heart function, blood circulation and the release of epinephrine (adrenaline) from the adrenal gland. Caffeine can increase alertness, which may improve simple reaction time. Large doses may adversely affect performance in events characterized by fine motor skills and control of hand steadiness. Earlier studies revealed that caffeine would not improve performance in events characterized by strength, speed, power or local muscular endurance; nor in endurance events that last less than 30 minutes. Recent studies have shown that caffeine induced improvement exists in several high intensity tasks. 

One of the most observed effects as rest is an increase in blood levels of FFA. Caffeine may raise serum FFA levels at rest, just before exercise. Significantly higher levels of FFA during exercise have been reported in subjects who are not regular caffeine users or who have abstained from caffeine use for 4-7 days, using large doses of caffeine. The current belief is that caffeine will enhance the metabolism of FFA, either the FFA delivered in the plasma or the FFA derived from the intramuscular stores of triglycerides.

Current data suggests that caffeine ingestion prior to exercise will induce a glycogen sparing effect. As the duration of the endurance event increases to an hour or more, caffeine may enhance performance. Caffeien may exert a stimulating effect on psychological processes, such as alertness and mood; which may diminish the perception of effort during exercise and thereby improve performance.

Whereas previous research has shown that carbohydrate loading and having a high-carbohydrate breakfast prior to competition may negate the metabolic effects of caffeine, recent research suggests it doesn’t appear to affect the ergogenic effect of caffeine adversely. One of the more important factors determining whether caffeine is an effective ergogenic aid is the caffeine status of the subjects. Consuming caffeine as a capsule in water significantly improved exercise performance on a treadmill while drinking the same does in coffee did not. Caffeine combined with ephedrine may enhance exercise performance in maximal tasks, however the use of ephedrine in any dose is prohibited.

Interestingly, the International Olympic Committee banned the use of caffeine as a drug prior to the 1972 Olympics. Because caffeine is a natural ingredient in some beverages that athletes consume, the IOC removed it from the doping list from 1972 to 1982. It was once again banned for the 1984 games, because research suggested that caffeine could artificially improve performance. Olympic athletes were permitted to consume small amount of caffeine, but the use of large doses were grounds for disqualification. Until 2004, the maximal dose that could be used without exceeding the legal limit for doping was 8-10 mg/kg body weight. The equates to approximately 4-6 cups of coffee or 3 Vivarin tablets.