The Effect of a Multi-Ingredient High Caffeine Pre-Exercise Supplement on Strength Power and Body Composision in 8 Weeks of Resistance Training

Abstract

Pre-workout supplements are broadly marketed to athletes and recreational exercisers with claims of improved performance or exercise effectiveness. Many such supplements contain a variable blend of known ergogenic aids and often include caffeine. PURPOSE: The purpose of this study was to examine the effects of a multi-component high caffeine pre-workout supplement on lean body mass (LBM) and measures of muscle performance during an eight week strength training exercise program. METHODS: Thirty physically active, resistance trained, college age (19.5 ± 0.269 yr) males were recruited for this double blind taste placebo control investigation. Subjects were randomly assigned into 2 groups: 1) Experimental (EXP) (n = 15) and 2) Control (CON) (n = 15). Subjects in the EXP drank the supplement containing a variety of common ergogenic aids including 450mg caffeine 15 minutes before each training session. Subjects in the CON drank a non-caloric placebo mixture at the same times. Both groups completed an eight week exercise program consisting of three days of strength training per week and all subjects completed the same training protocol. The following tests were performed prior to the training protocol and after 8 weeks of training: Body Weight, Body Composition via dual-energy X-ray absorptiometry (DEXA); maximal strength was determined using 1 RM tests for 8 different exercises; squat and bench press power was determined using an external dynamometer; and vertical jump. Twenty-five subjects completed the training protocol (EXP n = 14 and CON n = 11). Separate repeated measures ANOVAs were performed to test for differences between EXP and CON groups for strength, power, and body composition. The criteria for statistically significant differences were identified as an p value ≤ 0.05. RESULTS: A main effect for time was identified for each of the 1RM strength measures tested (p<0.05) except biceps curls (p = 0.34). A significant group x time interaction was found for the bench press exercise (F1/22 = 4.843, p = 0.039). Significant main effects were found for lean body mass (F1/22 = 20.32, p<0.001), but there were no significant group × time interactions for changes in LBM (F1/22 = 0.142 p = 0.710). Squat power measurements also showed a significant group x time interaction (F1/22 = 4.857, p = 0.038). Vertical Jump and bench press power did not differ between groups. CONCLUSIONS: Significant improvements in strength and lean body mass were observed in both the EXP and CON groups as would be expected with a resistance exercise training program. The primary purpose of this study was to examine the effectiveness of the supplement as an ergogenic aid. Two measures of muscle performance, bench press 1RM and squat power, increased more in the EXP group, but LBM changes did not differ. PRACTICAL APPLICATIONS: 8 weeks of pre-workout supplementation may provide some muscle performance benefit when combined with resistance exercise training. Significant improvements in LBM over the placebo drink were not observed however. ACKNOWLEDGEMENT: This study was funded by LaBrada Nutrition Inc, Houston, TX. *Denotes Equal Author Contribution