Influence of A Thermogenic Dietary Supplement on Safety Markers, Body Composition, Energy Expenditure, Muscular Performance and Hormone Concentrations: A Randomized, Placebo-Controlled, Double-Blind Trial
Grant M. Tinsley1, Stacie Urbina2, Jacy Mullins2, Jordan Outlaw2, Sara Hayward3, Matt Stone4, Cliffa Foster2, Colin Wilborn2,3, Lem Taylor2,
1 Department of Kinesiology & Sport Management, Texas Tech University, Lubbock, TX
2 Department of Exercise & Sports Science, Human Performance Lab, University of Mary Hardin-Baylor, Belton, TX
3 Department of Physical Therapy, University of Mary Hardin-Baylor, Belton, TX
4 Exercise Science Research Center, University of Arkansas, Fayetteville, AR, USA
Lem Taylor ✉ Department of Exercise & Sports Science, Human Performance Lab, University of Mary Hardin-Baylor, Belton, TX 76531, USA
Received: 22-06-2017 -- Accepted: 25-08-2017 --
Published (online): 01-12-2017
Dietary supplementation is commonly employed by individuals seeking to improve body composition and exercise performance. The purpose of the present study was to examine the safety and effectiveness of a commercially available dietary supplement designed to promote thermogenesis and fat loss. In a randomized double-blind trial, participants were assigned to consume placebo or a multi-ingredient supplement containing caffeine, green tea extract, l-carnitine, evodiamine and other ingredients that purportedly enhance thermogenesis. The study included acute baseline testing, a 6-week progressive resistance training and supplementation intervention, and post-intervention testing. Laboratory assessments included resting energy expenditure responses to acute supplement ingestion, evaluation of body composition and muscular performance, and analysis of blood variables (metabolic panel, testosterone, estrogen and cortisol). Dependent variables were analyzed using ANOVA with repeated measures. No unfavorable effects of supplementation were reported, and the supplement did not adversely affect safety markers. However, the supplement did not reduce fat mass or increase lean mass relative to placebo. In the supplement group, lower body maximal strength was increased relative to placebo (+18%, d=1.1 vs. +10%, d=0.5), and cortisol concentrations were decreased relative to placebo (-16%; d=-0.4 vs. +15%, d=.75). However, no differences were observed for upper body maximal strength or muscular endurance. REE increased in response to both supplement and placebo ingestion (placebo: +5%; supplement: +11.5%), but the difference between conditions was not statistically significant. Overall, some select parameters may have been beneficially modified by supplementation, but this did not result in superior weight or fat loss over 6 weeks of supplementation and resistance training.
Grant M. Tinsley, Stacie Urbina, Jacy Mullins, Jordan Outlaw, Sara Hayward, Matt Stone, Cliffa Foster, Colin Wilborn, Lem Taylor,
Influence of A Thermogenic Dietary Supplement on Safety Markers, Body Composition, Energy Expenditure, Muscular Performance and Hormone Concentrations: A Randomized, Placebo-Controlled, Double-Blind Trial.
Journal of Sports Science and Medicine(16), 459 - 467.
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