Impact Of A Caffeine-based Energy Drink On Fat Oxidation And Cycling Performance In Active Adults

PURPOSE: This study assessed the effects of a 200 mg caffeine-based energy drink on fat oxidation rates and cycling time trial (TT) performance. METHODS: Fifteen healthy, physically active participants (11 M, 4 F; 31 ± 7 years, 173.87 ± 8.90 cm, 80.63 ± 9.38 kg, 26.66 ± 2.43 kg/m2) completed a randomized, double-blind, crossover study. Participants attended two sessions, consuming a beverage containing 200 mg of caffeine (CAF) or placebo (PLA) 30 minutes before 45 minutes of cycling at 60% VO2Peak, with gas exchange data collected every 5 minutes to evaluate energy expenditure (EE) and fat oxidation followed by a 15-minute TT on a cycle ergometer. Visual analog scales (VAS) for energy and fatigue were recorded at baseline, 15 minutes post-supplementation, immediately post-TT, and 60 minutes post-TT. Ratings of perceived exertion were recorded before and after 45 minutes of cycling and after 15-minute TT. RESULTS: Group x time interaction for fat oxidation were not significant (p = 0.587). However, CAF showed a trend toward increased fat oxidation over time (p = 0.086), though post-hoc tests revealed no significant time-point differences. EE increased over time in both groups (p < 0.001), with CAF showing a significant increase compared to PLA 1-hour post-exercise (p = 0.045). TT (distance covered) (CAF: 11,411 ± 2,494 vs. PLA: 11,109 ± 2,403 meters, p = 0.104, d = 0.449) and perceived difficulty (RPE) (p = 0.334) were similar between groups. VAS scores indicated no significant differences between CAF and PLA for energy or fatigue. CONCLUSION: A 200 mg caffeine-based energy drink did not significantly affect fat oxidation rates or improve cycling TT performance, nor did it lead to differences in perceived energy or fatigue compared to placebo. These findings suggest that while caffeine may not influence fat oxidation, cycling performance, or subjective feelings of energy and fatigue in this context, other factors may play a role in its potential ergogenic effects. Supported by: Accelerator Active Energy, Newport Beach, CA