The Acute Effects of a Multi-Ingredient Herbal Supplement on Performance Fatigability: A Double-Blind, Randomized, and Placebo-Controlled Trial

Abstract

The purpose of the present study was to examine the acute effects of an herbal supplement containing a 70:30 blend of Rhaponticum carthamoides extract and Rhodiola rosea extract, respectively, on performance fatigability and the affective responses prior to and following exercise. Thirty men (age = 22.3 ± 4.1 years) volunteered for this randomized, placebo-controlled, double-blind, cross-over study. Following familiarization, participants visited the laboratory on three separate occasions where they consumed one 350 mg dose, a 175 mg dose of the supplement plus 175 mg of maltodextrin, or a placebo. Participants completed feeling, arousal, and mood surveys at supplement ingestion and following testing. Ninety minutes following ingestion, participants performed five sets of 30 maximal, concentric, leg extension muscle actions at 180°/sec, with one minute of rest between sets. Peak torque, average torque, and total work were calculated for each set, and the rating of perceived exertion (RPE) was assessed after each set. Data were analyzed with a repeated measures analysis of variance and intent-to-treat approach. For the performance variables, there was no interaction (p ≥ 0.317) or treatment effect (p ≥ 0.660), however, all torque variables decreased across sets and plateaued at sets 4-5, whereas RPE increased across sets (p < 0.001). For the affective responses, there was no interaction (p ≥ 0.781) or treatment effect (p ≥ 0.314); however, participants felt better, had an improved mood, and felt more aroused following testing (p < 0.047). This combination of herbal extracts likely does not acutely influence performance fatigability during high-intensity, repeated muscle actions.

Keywords:

• Rhodiola rosea
• rhaponticum carthamoides
• nutrition supplementation
• dietary supplements
• muscle strength
• fatigue

Acknowledgements

We would like to thank Megan Laffan, Abigail Trivisonno, Alexis Pihoker, Austin Peterjohn, Kara Anderson, Greg Nuckols, Dale Keith, Katie Kennedy, Addison Debord, Shawn Ahuja, Assem Patel, Savannah Leigh, and Meg McManus for their help with data collection. This study was funded by a research grant from Naturex SA.

Declaration of interest

ETT earns income as a writer and practitioner within the fitness industry, but does not directly profit from the sale of any dietary supplement.

Additional information

Funding

This work was supported by Naturex, SA.

Notes on contributors

Eric D. Ryan

Eric D. Ryan, PhD is a Stallings Scholar and Associate Professor at the University of North Carolina at Chapel Hill.

Gena R. Gerstner

Gena R. Gerstner, PhD is an Assistant Professor at Old Dominion University.

Jacob A. Mota

Jacob A. Mota, PhD is an Assistant Professor at the University of Alabama.

Eric T. Trexler

Eric T. Trexler, PhD is the Director of Education for Stronger by Science in Chapel Hill, NC.

Hayden K. Giuliani

Hayden K. Giuliani, MA is a research assistant at the University of North Carolina at Chapel Hill.

Malia N. M. Blue

Malia N.M. Blue, PhD is an Assistant Professor at High Point University.

Katie R. Hirsch

Katie R. Hirsch, PhD is a Postdoctoral Fellow at the Center for Translational Research in Aging and Longevity at the University of Arkansas for Medical Sciences.

Abbie E. Smith-Ryan

Abbie E. Smith-Ryan, PhD is an Associate Professor at the University of North Carolina at Chapel Hill.