The Effects of a Pre-Workout Supplement on Strength, Endurance and Mood

Nova Southeastern University, Davie, Florida, USA

Objective. The purpose of this study was to assess the acute effects of consuming a pre-workout supplement on indices of muscular strength, endurance and mood states. Background. Earlier research has shown that various pre-workout supplements may aid exercise performance; however, when the placebo is matched for caffeine content with a supplement, it is not known if an ergogenic effect may occur. Methods. Fourteen exercise-trained subjects (7 female, 7 male) participated in this investigation. Subjects came to the lab twice with at least 7 days between testing sessions. The consumption of product or placebo was randomized. They arrived at the lab 3 hours fasted with no prior exercise that day. Subsequently, they consumed the supplement or placebo (mixed with 8-12 ounces of water) 30 minutes prior to testing. Participants’ mood was also assessed via a profile mood states questionnaire (POMS) 30 minutes after product or placebo was consumed. After taking the POMS questionnaire, subjects had their exercise performance assessed via the 1-RM bench press followed by bench press repetitions to failure at 60% of 1-RM with 30 seconds rest between sets (3 total sets). Results. There were significant differences (p < 0.05) between the supplement and placebo for the number of repetitions to failure as well as total weight lifted. However, there were no differences for any of the other parameters measured. Conclusion. The results demonstrated that the acute consumption of a pre-workout supplement can enhance muscular endurance; however, it has no effect on strength or mood states.