Effect of a pre-workout energy supplement on acute multi-joint resistance exercise

The effect of a pre-workout energy supplement on acute multijoint resistance exercise was examined in eight resistancetrained college-age men. Subjects were randomly provided either a placebo (P) or a supplement (S: containing caffeine, taurine, glucuronolactone, creatine, β-alanine, and the amino acids; leucine, isoleucine, valine, glutamine and arginine) 10 minutes prior to resistance exercise. Subjects performed 4 sets of no more than 10 repetitions of either barbell squat or bench press at 80% of their pre-determined 1 repetition-maximum (1RM) with 90 seconds of rest between sets. Dietary intake 24 hours prior to each of the two training trials was kept constant. Results indicate that consuming the pre-workout energy drink 10 minutes prior to resistance exercise enhances performance by significantly increasing the number of repetitions successfully performed (p = 0.022) in S (26.3 ± 9.2) compared to P (23.5 ± 9.4). In addition, the average peak and mean power performance for all four sets was significantly greater in S compared to P (p < 0.001 and p < 0.001, respectively). No differences were observed between trials in subjective feelings of energy during either pre (p = 0.660) or post (p = 0.179) meaures. Similary, no differences between groups, in either pre or post assessments, were observed in subjective feelings of focus (p = 0.465 and p = 0.063, respectively), or fatigue (p = 0.204 and p = 0.518, respectively). Results suggest that acute ingestion of a highenergy supplement 10 minutes prior to the onset of a multi-joint resistance training session can augment training volume and increase power performance during the workout.