In fact, a buy VX-680 significant increase in exercise intensity was reported for the final 15 min (an all out portion of the exercise bout) for the caffeine + carbohydrate and electrolyte beverage, but not for the carbohydrate + electrolyte drink, or placebo. In conclusion, no significant differences in blood volume were present for any of the three treatments; therefore, caffeine did not adversely affect hydration and thus performance of long duration PRI-724 nmr in highly trained
endurance athletes [92]. Finally, Del Coso and colleagues [93] examined the effects of a moderate dose of caffeine in combination with sustained cycling at 60% VO2max. Seven endurance-trained males consumed each of the following conditions during 120 min of exercise: no rehydration, water, carbohydrate-electrolytes solution, and each of these three treatments with the addition of caffeine at 6 mg/kg
in capsule form. Results were conclusive, and indicated caffeine alone at 6 mg/kg did not significantly affect sweat rate during exercise, nor did ingestion of caffeine in combination with water or a carbohydrate-electrolytes solution. In addition, heat dissipation was not negatively affected [93]. this website Therefore, while there may be an argument for caffeine-induced dieresis at rest, the literature does not indicate any significant negative effect of caffeine on sweat loss and thus fluid balance during exercise that would adversely affect performance. Caffeine and Doping It has been shown that caffeine supplementation in the range of 3-6 mg/kg can significantly enhance both endurance and high-intensity performance in trained athletes. Consequently, the International Olympic SPTBN5 Committee mandates an allowable limit of 12 μg of caffeine per ml of urine [6, 15]. A caffeine dose in the range of 9 – 13 mg/kg approximately one hour prior to performance will reach the maximum allowable urinary concentration for competition
[6]. Caffeine consumption and urinary concentration is dependent on factors such as gender and body weight [94]. Therefore, consuming 6-8 cups of brewed coffee that contain approximately 100 mg per cup would result in the maximum allowable urinary concentration [15, 94]. According to The National Collegiate Athletic Association, urinary concentrations after competition that exceed 15 μg/ml are considered to be illegal [95]. In addition, the World Anti-Doping Agency does not deem caffeine to be a banned substance [96], but has instead included it as part of the monitoring program [97] which serves to establish patterns of misuse in athletic competition. Conclusion The scientific literature associated with caffeine supplementation is extensive. It is evident that caffeine is indeed ergogenic to sport performance but is specific to condition of the athlete as well as intensity, duration, and mode of exercise.