A Randomised, Placebo-Controlled, Crossover Study Investigating the Optimal Timing of a Caffeine-Containing Supplement for Exercise Performance

Abstract

Background Pre-exercise supplements containing low doses of caffeine improve endurance exercise performance, but the most efficacious time for consumption before intense endurance exercise remains unclear, as does the contribution of caffeine metabolism. Methods This study assessed the timing of a commercially available supplement containing 200 mg of caffeine, 1600 mg of β-alanine and 1000 mg of quercetin [Beachbody Performance Energize, Beachbody LLC, USA] on exercise performance, perception of effort and plasma caffeine metabolites. Thirteen cyclists (V̇O2max 64.5 ± 1.4 ml kg− 1 min− 1 (± SEM)) completed four experimental visits consisting of 30 min of steady-state exercise on a cycle ergometer at 83 ± 1% V̇O2max followed by a 15-min time trial, with perceived exertion measured regularly. On three of the visits, participants consumed caffeine either 35 min before steady-state exercise (PRE), at the onset of steady-state (ONS) or immediately before the time trial (DUR) phases, with a placebo consumed at the other two time points (i.e. three drinks per visit). The other visit (PLA) consisted of consuming the placebo supplement at all three time points. The placebo was taste-, colour- and calorie-matched. Results Total work performed during the time trial in PRE was 5% greater than PLA (3.53 ± 0.14 vs. 3.36 ± 0.13 kJ kg− 1 body mass; P = 0.0025), but not ONS (3.44 ± 0.13 kJ kg− 1; P = 0.3619) or DUR (3.39 ± 0.13 kJ kg− 1; P = 0.925), which were similar to PLA. Perceived exertion was lowest during steady-state exercise in the PRE condition (P < 0.05), which coincided with elevated plasma paraxanthine in PRE only (P < 0.05). Conclusion In summary, ingestion of a pre-exercise supplement containing 200 mg caffeine 35 min before exercise appeared optimal for improved performance in a subsequent fatiguing time trial, possibly by reducing the perception of effort. Whether this was due to increased circulating paraxanthine requires further investigation. Trial registration ClinicalTrials.Gov,NCT02985606; 10/26/2016.

Effects of CYP1A2 and ADORA2A Genotypes on the Ergogenic Response to Caffeine in Professional Handball Players

“…These data are in agreement with the results from other intermittent sports such as tennis in which caffeine ingestion improved the number of successful shots during a serve tennis performance test with minimal influence of the CYP1A2 genotype [36]. These combined results, in terms of genotype, reinforce the idea that the CYP1A2 genotype has little influence on the ergogenic response to caffeine, as previously found in other forms of exercise [11,23,24,[32][33][34][35][36]. Thus, despite findings associated with a higher ergogenic response to caffeine in CYP1A2 AA athletes with respect to C-allele athletes [22,29], the current investigation suggests that the ergogenic effect of caffeine on neuromuscular performance may be independent of the −163 C > A CYP1A2 genotype, at least in handball players.…”

“…However, to date, findings have been controversial, with some studies reporting a higher response to caffeine in AA athletes [22,29] and other studies showing a better response to caffeine in C-carrier athletes [30]. Overall, most of the investigations have found that the ergogenic response to caffeine is independent of the CYP1A2 −163 C > A polymorphism [11,23,24,[31][32][33][34][35][36].…”

Energy Drinks and Sports Performance, Cardiovascular Risk, and Genetic Associations; Future Prospects

“…One study report on caffeine consumption derived from energy drinks in cyclists, presented by Davenport et al [111]. They found that a 200 mg supplement of caffeine 35 min before exercise seemed optimal to improve performance in a time trial, reducing the perception of effort in which the individuals with genotype AA of CYP1A2.…”

CYP1A2 genotype and acute ergogenic effects of caffeine intake on exercise performance: a systematic review

“…Several studies explored the effects of caffeine supplementation on exercise performance while considering CYP1A2 −163C>A polymorphism [9][10][11][12][13]. The results of these studies, however, are equivocal.…”