Caffeine Effects on Sports-Related Performance

" There are at least five categories of ergogenic aids. These include mechanical, mental, physiologicalal, pharmacological, and nutritional aids. Ergogenic medicates are diligent primarily to "bestow energy or otherwise fire athletic performance (2:205)."

Although most drugs with ergogenic potential are verboten from competition, caffein is allowed in moderate amounts. Caffeine is one of deuce-ace different xanthine derivatives. The other two, theobromine and theophylline, are found in umber and tea, respectively. All three drugs produce similar physiologic set up (11:435-436).

Upon consumption, xanthine derivatives are completely absorbed from the gastrointestinal tract. They then deal out throughout the entire organism; their distribution correlates closely with that of dead body water. In particular, the compounds achieve their highest concentrations within skeletal muscle (9:215-219). In addition, the xanthine derivatives are highly lipid soluble, and readily cross the blood-brain barrier. This is purview to occur both by diffusion and also by a saturable transport system (8:139-155). Peak blood levels usually occur within approximately 30 to 60 proceedings (11:435-436). The brain concentration of caffein may then live stable for at least an hour (8:139-155).

Moderate doses of caffeine act as a "mild stimulant (8:139-155)." The drug is primarily us

Of the three mechanisms of caffeine action, perhaps the most important is the drug's antagonistic action on the adenosine receptors. The mobilization of intracellular calcium and the inhibition of phosphodiesterases occurs only at high caffeine concentrations. Adenosine receptor inhibition, however, occurs at physiologic caffeine concentrations (8:139-155).

In addition, Sutherland's group (1962; 1970) discovered that the methylxanthines inhibit the cyclic home phosphodiesterases. The researchers used theophylline and caffeine during their investigations of glycogen metabolism and peripheral lipolysis. First they identified the regulatory role of cyclic-3',5'-adenosine monophosphate (cAMP) in these processes.

Then, presently afterward, Sutherland and his coworkers observed that methylxanthine inhibits cyclic nucleotide phosphodiesterase, and thereby prevents cAMP's breakdown. The researchers therefore postulated that the physiologic make of caffeine result from the accumulation of cAMP and the "potentialization of its effects in order to stimulate the action of substances such as catecholamines (9:215-219)."

7. Jacobson, B. H.; Edwards, S. W. Influence of two levels of caffeine on maximal torsion at selected angular velocities. The Journal of Sports Medicine and Physical fitness 31:147-153; 1991, June.

In addition, investigators have more recently suggested that the psychological stimulant effects of caffeine may be link up to increased epinephrine levels (13:S344-S347). Catecholamines help the body adjust to the nervous strain of exercise. For instance, they contribute to such critical processes as glycogenolysis, glucose uptake, gluconeogenesis, muscle and fatty lipolysis, contractility, inotropic and chronotropic responses of the heart, and circulatory system adjustments (8:139-155). Caffeine has been found to increase levels of germ plasm catecholamines both during and at the end of exercise. LeBlanc et al. (1985) showed that decreased resting
Ordercustompaper.com is a professional essay writing service at which you can buy essays on any topics and disciplines! All custom essays are written by professional writers!