Caffeinated sports drink: ergogenic effects and possible mechanisms.
This double-blind experiment examined the effects of a caffeinated sports drink during prolonged cycling in a warm environment. Sixteen highly trained cyclists completed 3 trials: placebo, carbohydrate-electrolyte sports drink (CES), and caffeinated sports drink (CES+CAF). Subjects cycled for 135 min, alternating between 60% and 75% VO2max every 15 min for the first 120 min, followed by a 15-min performance ride. Maximal voluntary (MVC) and electrically evoked contractile properties of the knee extensors were measured before and after cycling. Work completed during the performance ride was 15-23% greater for CES+CAF than for the other beverages. Ratings of perceived exertion were lower with CES+CAF than with placebo and CES. After cycling, the MVC strength loss was two-thirds less for CES+CAF than for the other beverages (5% vs. 15%). Data from the interpolated-twitch technique indicated that attenuated strength loss with CES+CAF was explained by reduced intrinsic muscle fatigue.
Cureton
Kirk J
KJ
Department of Kinesiology, University of Georgia, Athens, GA 30602-6554, USA.
Warren
Gordon L
GL
Millard-Stafford
Mindy L
ML
Wingo
Jonathan E
JE
Trilk
Jennifer
J
Buyckx
Maxine
M
D000328:Adult; D019540:Area Under Curve; D001642:Bicycling / Q000502:physiology*; D002110:Caffeine / Q000494:pharmacology*; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000187:drug effects* / Q000502:physiology; D010101:Oxygen Consumption / Q000187:drug effects* / Q000502:physiology; D005082:Physical Exertion / Q000187:drug effects / Q000502:physiology
D000697:Central Nervous System Stimulants; D002110:Caffeine