LOW-DOSE CAFFEINE IS NOT PERFORMANCE-ENHANCING
Ryan, E. J., Kim, C. Muller, M. D. Jankowski-Wilkinson, A., Russell, M., Bliss, M. V., Bellar, D. M., Otterstetter, R., Barkley, J. E., Glickman, E. L., & Kamimori, G. H. (2009). Low dose caffeine does not enhance cycle time to exhaustion. ACSM 56th Annual Meeting, Seattle, Washington. Presentation number 875.
"Research has demonstrated that caffeine may improve physical and cognitive performance. Stay Alert™ chewing gum (100mg caffeine/piece) has been utilized by military personnel to improve physical and cognitive performance and offers a quick and effective delivery of caffeine via the buccal mucosa." This study determined if low dose (200 mg) caffeine (via chewing gum) administered at different time points would enhance cycling time to exhaustion. Healthy, active, college volunteers (N = 8) participated in five separate laboratory sessions, with a one week washout period between each visit. During the first visit, Ss underwent a graded exercise test on a cycle ergometer to determine maximal oxygen consumption (VO2max). For each of the next four visits Ss cycled at 85% VO2max until exhaustion and total cycle time to exhaustion was recorded. VO2 , respiratory exchange ratio, and heart rate measures were obtained prior to and every 10 minutes during cycling. Two pieces of chewing gum, one a placebo and the other caffeine-based Stay Alert™ were administered in a randomized, counterbalanced, double blind manner at three time points (35 minutes pre-exercise, 5 minutes pre-exercise, and 15 minutes following initiation of exercise). For the fourth visit, placebo gum was administered at all three time points.
Dose schedule revealed an expected main effect of time for increases in VO2 , respiratory exchange ratio, and heart rate. There was no significant main or interaction effect of dose schedule or treatment for total cycle time, VO2 , respiratory exchange ratio, or heart rate.
Implication. Low dose caffeine does not enhance cycle time to exhaustion nor differentially effect VO2 , respiratory exchange ratio, or heart rate.
This study demonstrates that there is a critical level of a drug dose that needs to be exceeded for it to have a performance-enhancing effect. The mere presence of a "banned substance" is insufficient to infer performance-enhancement potential. That factor is not considered in WADA's dubious dictates.P>
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