Exercise endurance 1, 3, and 6 h after caffeine ingestion in caffeine users and nonusers

Abstract

Bell, Douglas G., and Tom M. McLellan. Exercise endurance 1, 3, and 6 h after caffeine ingestion in caffeine users and nonusers. J Appl Physiol 93: 1227-1234, 2002. First published May 17, 2002 10.1152/japplphysiol.00187.2002The purpose of the present study was to examine the duration of caffeine's ergogenic effect and whether it differs between users and nonusers of the drug. Twenty-one subjects (13 caffeine users and 8 nonusers) completed six randomized exercise rides to exhaustion at 80% of maximal oxygen consumption after ingesting either a placebo or 5 mg/kg of caffeine. Exercise to exhaustion was completed once per week at either 1, 3, or 6 h after placebo or drug ingestion. Exercise time to exhaustion differed between users and nonusers with the ergogenic effect being greater and lasting longer in nonusers. For the nonusers, exercise times 1, 3, and 6 h after caffeine ingestion were 32.7 Ϯ 8.4, 32.1 Ϯ 8.6, and 31.7 Ϯ 12.0 min, respectively, and these values were each significantly greater than the corresponding placebo values of 24.2 Ϯ 6.4, 25.8 Ϯ 9.0, and 23.2 Ϯ 7.1 min. For caffeine users, exercise times 1, 3, and 6 h after caffeine ingestion were 27.4 Ϯ 7.2, 28.1 Ϯ 7.8, and 24.5 Ϯ 7.6 min, respectively. Only exercise times 1 and 3 h after drug ingestion were significantly greater than the respective placebo trials of 23.3 Ϯ 6.5, 23.2 Ϯ 7.1, and 23.5 Ϯ 5.7 min. In conclusion, both the duration and magnitude of the ergogenic effect that followed a 5 mg/kg dose of caffeine were greater in the nonusers compared with the users. time to exhaustion; ergogenic aid; drug sensitivity THERE HAVE BEEN NUMEROUS STUDIES and reviews indicating that caffeine ingested before exercise causes rapid and significant improvements in performance, especially in aerobic exercise capacity (6,8,16,20,28,30). The dose of caffeine studied has ranged from 1 to 15 mg/kg of body mass. The optimal dose has not been determined because it may vary according to the sensitivity of the individual to caffeine. However, doses between 3 and 6 mg/kg produce an equivalent ergogenic effect to higher doses (5, 29), and this has led Graham et al. (17) to suggest that the optimal dose thus lies in this lower range.Even though caffeine has a half-life of 4-6 h that implies high levels of caffeine will be in the blood for up to 3-4 h after ingestion, most studies have focused on exercise performance ϳ1 h after ingestion. The assumption is that the ergogenic effect is related to the circulating level of the drug in the blood. Thus maximal effects are assumed to occur ϳ1 h after ingestion, when peak blood concentrations are observed (2, 14). Some studies (27,35) have suggested that waiting 3 h may be more optimal because the caffeine-induced effect on lipolysis is greater than at earlier times after ingestion. However, the hypothesis that the ergogenic effect from caffeine is due to an enhanced free fatty acid mobilization and tissue utilization has not found much support in the recent literature (16,17,29).For sustained operations, as is quite commo...

Effects of Acute Caffeine Consumption on Sodium-Aided Hyperhydration

“…In contrast, Ryan et al [20] observed improved endurance performance when caffeine was consumed 5 min prior to exercise but not when it was consumed 60 or 120 min before exercise. Finally, Bell and McLellan [21] noted similar ergogenic effects on exercise time to exhaustion when subjects consumed caffeine at either 1, 3, or 6 h before the beginning of exercise.…”

Elevação da natremia induzida pela cafeína durante o exercício

“…Experimentos controlados examinaram a farmacocinética e a dose-dependência da cafeína no repouso e durante o exercício (Grahan & Spriet 1991Jackman, 1996;Evans & Griffets, 1998); estes dados nos levaram à escolha da dose de 5 mg.Kg -1 , antevendo um aumento no rendimento físico dos atletas durante a experimentação. Embora não estivessemos interessados na medida da performance, acreditamos que a dose recomendada para avaliar os efeitos do fármaco no balanço eletrolítico deveria ser aquela que estivesse vinculada ao aumento do rendimento, conforme anteriormente descrito (Bell, 2002;Cox, 2002;Greer, 2000, Mohr, 1998.…”

Caffeine improves volleyball serves precision among college male players

“…Also, in order to evaluate the effects of caffeine acute ingestion, Bell and Mclellan (3) studied the cycling performance until exhaustion in (15 male and 6 female) physicaly active subjects, who underwent 12 hs of caffeine abstinence.…”

“…We asked them not to exercise during the study in order to avoid the effects of caffeine tolerance, which may be developed in some subjects who consume caffeine chronically in certain diary amounts (3) . The players were asked not to ingest chocolate, alcoholic, or caf- Regarding the double-blind procedure, only a second researcher was aware about the capsule content, that is, neither the researcher who provided the capsules to the participants nor the participants knew whether they ingested caffeine or placebo, and in order to ensure a balance in the groups, the capsules ingestion was done through a block randomization.…”

“…Upon caffeine ingestion, there is a decrease in effort perception during exercise and delay in fatigue, thereby improving performance of anaerobic exercises (10) . These effects can be evidenced with between 3 to 9 mg·kg of caffeine ingestion (27,32) and persists even 3 hours after its acute ingestion for both caffeine consumers and non-consumers (3) .…”