Acceleration Tolerance After Ingestion of a Commercial Energy Drink

http://www.dtic.mil/docs/citations/ADA534177


Acceleration Tolerance After Ingestion of a Commercial Energy Drink


Walker, Thomas B. ; Balldin, Ulf ; Fischer, Joseph ; Storm, William ; Warren, Gordon L.


This study examined the ability of a commercial energy drink to enhance acceleration tolerance, strength under G-load, and cognitive performance immediately prior to and following acceleration exposure. Eight experienced centrifuge subjects completed three separate experimental acceleration exposures following ingestion of 11.5 ml/kg body weight of a)a commercial energy drink, providing 5.0 mg caffeine/kg body weight, b) a commercial energy drink without caffeine or c) placebo. The acceleration exposures consisted of a relaxed gradual onset run to peripheral light loss, a rapid onset run to 6.0 G for 15 s, and a simulated air combat maneuver (SACM) run of repeated alternations between 4.5 G for 15 seconds and 7G for 15 seconds until volitional exhaustion. Cognitive tests were performed prior to and after the acceleration profiles. Relaxed G-tolerance was significantly higher under the caffeine session, whereas SACM duration did not differ among the drink conditions. Hip adductor muscle strength was lower during the placebo session than during the other two sessions. Cognitive reaction time was faster post-acceleration than pre-acceleration, and faster under the caffeine condition than the placebo condition. We conclude that consumption of a caffeine-based energy drink enhances relaxed G-tolerance and may increase strength, but does not impact acceleration duration. We further conclude that cognitive reaction time is improved by the caffeinated drink, as well as by the physical exertion during the acceleration exposure.
Descriptors : *CAFFEINE, SIMULATION, REPRINTS, PERFORMANCE(HUMAN), COGNITION, STRENGTH(PHYSIOLOGY), ACCELERATION TOLERANCE, ENERGY, CENTRIFUGES, MUSCLES, EXPOSURE(PHYSIOLOGY), PLACEBOS, TEST AND EVALUATION, REACTION TIME