Effects of a Multi-Ingredient Preworkout Supplement Versus Caffeine on Energy Expenditure and Feelings of Fatigue during Low-Intensity Treadmill Exercise in College-Aged Males.

Daniel J Lutsch,Brandon J Cox,Clayton L Camic,Shaine E Henert,Andrew R Jagim,Riley R Stefan,Rachel N Tauber

doi:10.3390/sports8100132

Daniel J Lutsch, Brandon J Cox + Show 5 more

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https://doi.org/10.3390/sports8100132

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Journal: Sports	Publication Date: Sep 25, 2020
Citations: 3	License type: CC BY 4.0

Affiliation: Northern Illinois University, Mayo Clinic Health System

Abstract

The primary purpose of this study was to examine the acute effects of a multi-ingredient (i.e., caffeine, green tea extract, Yohimbe extract, capsicum annum, coleus extract, L-carnitine, beta-alanine, tyrosine) preworkout supplement versus a dose of caffeine (6 mg·kg−1) on energy expenditure during low-intensity exercise. The effects of these treatments on substrate utilization, gas exchange, and psychological factors were also investigated. Twelve males (mean ± SD: age = 22.8 ± 2.4 years) completed three bouts of 60 min of treadmill exercise on separate days after consuming a preworkout supplement, 6 mg·kg−1 of caffeine, or placebo in a randomized fashion. The preworkout and caffeine supplements resulted in significantly greater energy expenditure (p < 0.001, p = 0.006, respectively), 2 (p < 0.001, p = 0.007, respectively), CO2 (p = 0.006, p = 0.049, respectively), and E (p < 0.001, p = 0.007, respectively) compared to placebo (collapsed across condition). There were no differences among conditions, however, for rates of fat or carbohydrate oxidation or respiratory exchange ratio. In addition, the preworkout supplement increased feelings of alertness (p = 0.015) and focus (p = 0.005) 30-min postingestion and decreased feelings of fatigue (p = 0.014) during exercise compared to placebo. Thus, the preworkout supplement increased energy expenditure and measures of gas exchange to the same extent as 6 mg·kg−1 of caffeine with concomitant increased feelings of alertness and focus and decreased feelings of fatigue.

Highlights

Multi-ingredient preworkout supplementation has become a popular strategy for individuals attempting to improve feelings of energy and focus; muscular strength; endurance; muscle mass; blood flow; and fat loss during resistance and aerobic training, group exercise classes, as well as recreational activities [1]
Of the five ingredients with well-established recommended doses, caffeine was the only ingredient provided at an average quantity at or above its suggested ergogenic threshold [2]
There were no significant differences among conditions for total energy intake (F(2.22) = 0.447; p = 0.646; partial η2 = 0.039), fat (F(2.22) = 0.422; p = 0.661; partial η2 = 0.037), carbohydrate (F(2.22) = 0.906; p = 0.419; partial η2 = 0.076), or protein (F(2.22) = 1.419; p = 0.263; partial η2 = 0.114)

Summary

Introduction

Multi-ingredient preworkout supplementation has become a popular strategy for individuals attempting to improve feelings of energy and focus; muscular strength; endurance; muscle mass; blood flow; and fat loss during resistance and aerobic training, group exercise classes, as well as recreational activities [1]. A recent study [2] examined the common ingredient profiles of the top 100 best-selling preworkout supplements and reported that these products contain 18.4 ± 9.7 (mean ± SD) ingredients with the majority including beta-alanine (87%), caffeine (86%), citrulline (71%), tyrosine (63%), and taurine (51%). Their findings [2] indicated that 58% of these preworkout supplements have at least one proprietary blend with 64 ± 24% of all ingredients listed at Sports 2020, 8, 132; doi:10.3390/sports8100132 www.mdpi.com/journal/sports. Of the five ingredients (i.e., beta-alanine, caffeine, citrulline, creatine, and arginine) with well-established recommended doses, caffeine was the only ingredient provided at an average quantity at or above its suggested ergogenic threshold [2].

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