CAFFEINE PLUS ADDITIVES DOES NOT AFFECT STRENGTH OR ENDURANCE PERFORMANCE
Walter, A. A., Herda, T. J., Ryan, E. D., Costa, P. B., Hoge, K. M., Beck, T. W., Stout, J. R., & Cramer, J. T. (2009). Acute effects of a caffeine-containing thermogenic supplement on endurance performance and muscular strength in men. ACSM 56th Annual Meeting, Seattle, Washington. Presentation number 1902.
This study determined the effects of a thermogenic nutritional supplement on muscular strength, endurance performance, and rating of perceived exertion during cycle ergometry in college-aged men (N = 20). Testing took place over a three-week period, with three laboratory visits separated by seven days. During visit 1, a graded exercise test was performed on a cycle ergometer until exhaustion (increase of 25 W every two minutes) to determine the maximum cycle ergometry power output (W) at the VO2peak. In addition, one-repetition maximum (1 RM) strength was assessed for the bench press and leg press exercises. During visits 2 and 3, Ss consumed a capsule containing either the active supplement (200 mg caffeine, 33.34 mg capsaicin, 5 mg bioperine, and 20 mg niacin) or a placebo (175 mg of calcium carbonate, 160 mg of microcrystalline cellulose, 5 mg of stearic acid, and 5 mg of magnesium stearate in an identical capsule) 30 minutes prior to the testing. Testing included a time-to-exhaustion ride on a cycle ergometer at 80% of the previously-determined power output at VO2peak followed by 1 RM leg press and bench press tests. Rating of perceived exertion was also assessed throughout the time-to-exhaustion tests.
There were no differences between the active and placebo trials for bench press, leg press, time-to-exhaustion, or rating of perceived exertion. However, for the bench and leg-press scores, the baseline values (visit 1) were less than the values recorded during visits 2 and 3.
Implication. An active supplement containing caffeine, capsaicin, bioperine, and niacin did not alter muscular strength, cycling endurance, or rating of perceived exertion during a time-to-exhaustion cycling ergometer trial.
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