Effect of a pre-exercise energy drink (Redline®) on muscular endurance of the trunk

Background

Muscular endurance of the trunk is associated with successful performance in athletics, as well as activities of daily living. Furthermore, muscular endurance of the trunk may also play a critical role in injury prevention by allowing individuals to better withstand the effects of repetitive stressors. Pre-exercise, high energy supplements are frequently consumed as a method of improving exercise performance during an acute bout of exercise. Thus, the use of such supplements prior to an exercise session may allow the lifter to perform a greater total volume of work during training sessions. The purpose of this study was to investigate the effect of a high energy liquid supplement on a muscular endurance exerciseof the trunk.

Methods

Forty-one (n=41) healthy males (21.73 ± 1.74 yrs; 176.48 ± 7.54 cm; 81.16 ± 10.94 kg) volunteered to participate in this study. All test subjects completed a health history and caffeine usage questionnaires, as well as a consent form prior to participation. Subjects completed a pre and post sit-up to fatigue test within a week of one another. During the post-test session subjects were either given four ounces of an energy supplement (Redline by VPX) or a placebo, 30 minutes prior to testing. Administration of the supplement was double blind. Twenty-three (n=23) subjects received the supplement, while eighteen (n=18) subjects received the placebo. A 2 x 2 factorial ANOVA was used to determine between group differences for the muscular endurance assessments,at an alpha level of 0.10.

Results

Analysis of the data revealed a significant interaction at the alpha 0.10 level, F (1, 40) = 2.79, p = 0.075. As indicated, the degrees of freedom are limited by sample size; therefore, with more subjects in both the treatment and placebo group the expected outcome would be magnified. However, further examination of the data revealed an important finding, the sit-up scores of the treatment group were significantly higher for the posttest (59.00 ± 20.65) than the sit-up scores for the placebo group (53.06 ± 20.63). The treatment effect was further emphasized when comparing pretest sit-up scores. There was no significant difference in pretest sit-up scores between the groups (treatment: 52.13 ± 18.94, placebo: 53.44 ± 17.73), however posttest scores revealed significantly higher scores in the treatment group (13.2%) when compared to the placebo (- 0.7%).

Conclusions

The results of this study indicate thatthe pre-exercise liquid energy supplement investigated had a significant effect on upper-body muscular endurance as measured by the sit-up to fatigue test when taken within 30 minutes of the exercise bout.