Thirteen of 22 subjects in that investigation described feelings of greater energy, elevated heart rate, restlessness, and tremor. It should also be noted that these feelings were enhanced in participants who consumed little caffeine on a daily basis [76]. It would seem the important factor to consider is the individual habits of the athlete and how caffeine supplementation would affect their personal ability to perform. In terms of practical application, it is the responsibility of the coach and/or athlete to determine what dose of caffeine, if any, is suitable for competition. Caffeine and Hydration It has been widely suggested that caffeine consumption induces an acute state

of dehydration. However, consuming caffeine at rest check details and during exercise presents two entirely different scenarios. Specifically, studies examining the effects of caffeine-induced diuresis at Selleck Dactolisib rest can and should not be applied to athletic performance. To begin, a study published in 1928 by Eddy & Downs [84] examined the possible role of caffeine induced dehydration but included an n of only 3. In a review publication on caffeine and fluid balance, it was

suggested by Maughan and Griffin [85] that “”hydration status of the individual at the time of caffeine ingestion may also affect the response, but this has not been controlled in many of the published studies”". Despite the unfounded, but accepted, notion that caffeine ingestion may negatively alter fluid balance during exercise, Falk and colleagues [86] found no differences in total water loss or sweat rate following consumption of a 7.5 mg/kg dose of caffeine (5 mg/kg

2 hr prior to exercise, 2.5 mg/kg 30 min prior) and treadmill walking with a 22-kg backpack (intensity of ~70-75% VO2max). The authors did caution that exercise was carried out in a thermoneutral environment and additional research is warranted to determine effects in a more stressful environmental condition [86]. Wemple et al. [87] investigated the effects of a caffeinated versus non-caffeinated electrolyte solution drink at rest and during 180 Etomidate min of moderate-intensity cycling at 60% VO2max. In total, 8.7 mg/kg of caffeine was consumed in divided doses. Results indicated a significant increase in urine volume for caffeine at rest, but there was no significant difference in fluid balance for caffeine during exercise [87]. These results are noteworthy, because according to a review published by Armstrong [88], several research studies published between 1970 and 1990 reported outcome measures, such as loss of water and electrolytes, based on urine samples taken at rest and within 2-8 hours of supplementation [88]. Kovacs and colleagues [56] published similar results in a 1998 study that examined time trial performance and caffeine consumption in various dosages added to a carbohydrate-electrolyte solution (CES). In total, subjects consumed each carbohydrate-electrolyte drink with the addition of 150 mg, 225 mg, and 320 mg of caffeine.