Effects Of A Pre-exercise Supplement On Anaerobic Power And Blood Lactate In Males And Females

Abstract

Pre-workout supplements claim to enhance athletic performance, but these claims have not been evaluated in the context of repeated anaerobic power tests in males and females. Supplements often contain numerous ingredients proposed to work synergistically to enhance performance. PURPOSE: We compared the effects of a supplement containing only creatine (CRE) with a supplement containing creatine, beta-alanine, amino acids, caffeine, and B-vitamins (MULT) on maximal anaerobic power, fatigue, and blood lactate accumulation in males and females. It was hypothesized that MULT would be associated with greater anaerobic power, reduced fatigability, and reduced blood lactate levels compared to CRE, with both supplements greater than placebo (PL). METHODS: Male and female subjects (n=20) performed two 30 second Wingate anaerobic tests separated by a 5 minute rest period, 20 minutes after consuming PL, CRE, or MULT in a repeated measures, blinded design. Fatigue index was quantified as relative power drop over the duration of the test. Blood lactate levels were measured before test 1 and after tests 1 and 2. RESULTS: Peak anaerobic power was not different among all conditions for test 1 or 2 (average for all conditions were 11.5±0.5 and 11.3±0.5 W/kg for males, 9.0±1.1 and 8.8±1.2 W/kg for females). Fatigue index was similar for test 1 and 2 and was not different among conditions or genders. Respective test 1 fatigue index values for males and females were 40.5±2.7% and 37.75±2% for MULT, 43±1.7% and 41±3.4% for CRE, and 43.8±2.8% and 40.8±2.6% for PL. In both genders, increases in lactate from post-test 1 to post-test 2 were not different among conditions. Increases in lactate from pre-test 1 to post test 2 were also not different among conditions or genders with changes in MULT (8.6±0.8 and 8.4±1.2 mmol/L), CR (10.9±1.0 and 7.7±1.0 mmol/L) and PL (10.8±1.3 and 7.2±1.1 mmol/L) for males and females, respectively. CONCLUSION: Results suggest that MULT or CRE do not significantly increase peak anaerobic power, reduce fatigability or buffer increases in lactate with repeated anaerobic power tests compared to PL.