Do the Noncaffeine Ingredients of Energy Drinks Affect Metabolic Responses to Heavy Exercise?

Abstract

Energy drinks (EDs) such as Red Bull (RB) are marketed to enhance metabolism. Secondary ingredients of EDs (e.g., taurine) have been purported to improve time trial performance; however, little research exists on how such secondary ingredients affect aerobic metabolism during heavy exercise. The purpose of this study was to investigate the effect of the secondary ingredients of RB on aerobic metabolism during and subsequent to heavy exercise. In double-blind, counterbalanced, and crossover fashion, 8 recreationally trained individuals completed a graded exercise test to determine the gas exchange threshold (GET). Subjects returned on 2 separate occasions and ingested either a 245 ml serving of RB or a control (CTRL) drink with the equivalent caffeine before engaging in two 10-minute constant-load cycling bouts, at an intensity equivalent to GET, with 3 minutes of rest between bouts. Accumulated liters of O2 (10 minutes) were higher for the first bout (17.1 ± 3.5 L) vs. the second bout (16.7 ± 3.5 L) but did not differ between drinks. Similarly, excess postexercise oxygen consumption was higher after the initial bout (RB mean, 2.6 ± 0.85 L; CTRL mean, 2.9 ± 0.90 L) vs. the second bout (RB mean, 1.5 ± 0.85 L; CTRL mean, 1.9 ± 0.87 L) but did not differ between drinks. No differences occurred between drinks for measures of heart rate or rating of perceived exertion. These results indicate that the secondary ingredients contained in a single serving of RB do not augment aerobic metabolism during or subsequent to heavy exercise.

Acute administration of high doses of taurine does not substantially improve high-intensity running performance and the effect on maximal accumulated oxygen deficit is unclear

“…In line with this study, other recent studies did not show any ergogenic effects of taurine supplementation in different forms of exercise (Pettitt et al 2013). Pettitt et al (2013) did not show improvements in the aerobic metabolism (accumulated oxygen consumed and EPOC) after acute ingestion of an energy drink (caffeine + taurine) or control drink (equivalent caffeine content alone).…”

International Society of Sports Nutrition position stand: energy drinks

“…However, caffeine and carbohydrate may act in a synergistic manner [182]. To support this view, a recent paper by Pettitt et al [186] reported that while ingestion of an ED prior to exercise affected aerobic metabolism during and following cycling exercise, the secondary ingredients found in the ED had no additive effects.…”

The Effect of Ergogenic Supplements and Mediterranean Diet on Cycling Performance. Differences According to Duration and Intensity.

“…The ergogenic impact of caffeine is supported by a plethora of studies [8,26,30,34,35]. However, caffeine intake can provoke side effects such as headache, hypertension, tachycardia and gastrointestinal upset [11,51] and acts differently in every athlete [70].…”