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

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Creator
  • Outlaw, Jordan J
    • Other Affiliation: Human Performance Lab, University of Mary Hardin-Baylor, 900 College Street, Belton 76513, TX, USA
  • Taylor, Lem W
    • Other Affiliation: Human Performance Lab, University of Mary Hardin-Baylor, 900 College Street, Belton 76513, TX, USA
  • Hayward, Sara E
    • Other Affiliation: Human Performance Lab, University of Mary Hardin-Baylor, 900 College Street, Belton 76513, TX, USA
  • Foster, Cliffa A
    • Other Affiliation: Human Performance Lab, University of Mary Hardin-Baylor, 900 College Street, Belton 76513, TX, USA
  • Urbina, Stacie L
    • Other Affiliation: Human Performance Lab, University of Mary Hardin-Baylor, 900 College Street, Belton 76513, TX, USA
  • Wilborn, Colin D
    • Other Affiliation: Human Performance Lab, University of Mary Hardin-Baylor, 900 College Street, Belton 76513, TX, USA
  • Smith-Ryan, Abbie
    • Affiliation: College of Arts and Sciences, Department of Exercise and Sport Science
Abstract
  • 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; Δ-0.43 ± 0.58; p = 0.920), fat mass (Δ-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 (Δ100.5 ± 42.7W; p = 0.001), BPM (Δ8.0 ± 12.9 lbs; p = 0.001), and LPM (Δ80.0 ± 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.
Date of publication
Identifier
  • doi:10.1186/s12970-014-0040-0
  • 25302053
Resource type
  • Article
Rights statement
  • In Copyright
Rights holder
  • Jordan J Outlaw et al.; licensee BioMed Central Ltd.
License
Journal title
  • Journal of the International Society of Sports Nutrition
Journal volume
  • 11
Journal issue
  • 1
Page start
  • 40
Language
  • English
Is the article or chapter peer-reviewed?
  • Yes
ISSN
  • 1550-2783
Bibliographic citation
  • Journal of the International Society of Sports Nutrition. 2014 Aug 15;11(1):40
Access
  • Open Access
Publisher
  • BioMed Central Ltd
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