The long-term effects of pre-workout supplementation on resting energy expenditure and body composition in recreationally active females

Abstract

Multiple ingredient pre-workout supplements (MIPS) are purported to offer favorable acute metabolic changes potentially leading to improvements in body composition over time. However, there is limited information available regarding the long-term benefits, specifically in female populations. Therefore, the purpose of this study was to investigate the long term effects of MIPS on body composition and resting energy expenditure (REE) in recreationally active females participating in a resistance training (RT) program. Nineteen females participated in a randomized, double-blind, placebo controlled study. Experimental testing included body composition and REE measurements before and after a seven-week RT program while ingesting either a MIPS or placebo daily. Subjects were further instructed to follow dietary intake recommendations to elicit moderate weight loss. There were no significant group x time interactions for body fat percentage (p=0.66), fat-free mass (p=0.87), fat mass (p=0.63), REE (p=0.52), or respiratory exchange ratio (p=0.40). Significant overall main effects for time were observed between pre and midway testing for increases in fat-free mass (p<0.001) and decreases in body fat percentages (p=0.03). In conclusion, the results of this study suggests that seven weeks of MIPS supplementation does not promote any favorable changes in body composition or REE when combined with a structured RT program.