Acute effects of a commercially-available pre-workout supplement on markers of training: a double-blind study

Abstract

Background

Pre-workout supplements containing numerous ingredients claim to increase performance and strength. Product-specific research is important for identifying efficacy of combined ingredients. The purpose of this study was to evaluate the effects of a proprietary pre-workout dietary supplement containing creatine monohydrate, beta-alanine, L-Tarurine, L-Leucine, and caffeine, on anaerobic power, muscular strength, body composition, and mood states.

Methods

In a double-blind, randomized, matched-pair design, twenty male subjects (mean ± SD; 22.4 ± 9.5 yrs, 76.9 ± 11.2 kg, 22.7 ± 9.5% body fat), consumed either 30 g of a pre-workout supplement (SUP) or maltodextrin placebo (PLC) 30 minutes before a resistance training workout, after completing baseline testing. Body composition was determined via dual-energy x-ray absorptiometry (DEXA). Subjects completed 12 vertical jumps for height (VJ) and one repetition maximum (1RM) and repetitions to failure lifts on bench (BPM) and leg press (LPM). Finally, subjects completed a Wingate power test on a cycle ergometer [mean power (WMP) and peak power (WPP)]. After baseline testing, participants completed eight days of supplementation and four split-body resistance-training bouts. Side effect questionnaires were completed daily 30 minutes after consuming the supplement. Subjects completed post-supplement testing on Day 8. Data were analyzed utilizing a 2 × 2 repeated measures ANOVA [treatment (PLC vs SUP) × time (T1 vs T2)] and ninety-five percent confidence intervals.

Results

There were no significant treatment × time interactions (p > 0.05). There were no significant changes in %body fat (%BF; ∆-0.43 ± 0.58; p = 0.920), fat mass (∆-2.45 ± 5.72; p = 0.988), or lean body mass (LBM; 10.9 ± 12.2; p = 0.848). 95% CI demonstrated significant LBM increases for both groups. There was a main effect for time for WPP (∆100.5 ± 42.7W; p = 0.001), BPM (∆8.0 ± 12.9 lbs; p = 0.001), and LPM (∆80.0 ± 28.8 lbs; p = 0.001), with no significant differences between treatments. There was no significant difference in mood states between groups or over time.

Conclusion

The proprietary pre-workout blend combined with eight days of training did not significantly (ANOVA) improve body composition or performance. While not significant, greater gains in LPM were demonstrated in the SUP group for lean body mass and lower body strength. Future studies should evaluate more chronic effects of proprietary pre-workout blends on total training volume and performance outcomes.

Keywords:

• Body composition
• Pre-workout
• Creatine
• Beta-alanine
• Strength

Electronic supplementary material

The online version of this article (doi:10.1186/s12970-014-0040-0) contains supplementary material, which is available to authorized users.

Copyright comment

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Electronic supplementary material

The online version of this article (doi:10.1186/s12970-014-0040-0) contains supplementary material, which is available to authorized users.

Copyright comment

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Acknowledgements

We would like to thank Dymatize Inc. for funding this study. We would also like to thank all participants and laboratory assistants for their part in this research study.

Competing interests

The study was funded by Dymatize Inc. The authors do not have any competing interests.

Authors’ contribution

JO, CW, AS, and SH prepared the manuscript. SH, SU, and JO performed data collection. SH and AS performed statistical analysis. CW was the primary investigator and CF provided administrative oversight. LM assisted with manuscript editing and revisions. All authors read and approved the final manuscript.