Correction to: The Effect of Acute Caffeine Ingestion on Endurance Performance: A Systematic Review and Meta-Analysis

Abstract

Introduction Caffeine is a widely used ergogenic aid with most research suggesting it confers the greatest effects during endurance activities. Despite the growing body of literature around the use of caffeine as an ergogenic aid, there are few recent meta-analyses which quantitatively assess the effect of caffeine on endurance exercise. Objectives To summarise studies which have investigated the ergogenic effects of caffeine on endurance time-trial performance and to quantitatively analyse the results of these studies to gain a better understanding of the magnitude of caffeine's ergogenic effect on endurance time-trial performance. Methods A systematic review was carried out on randomised placebo-controlled studies investigating the effects of caffeine on endurance performance and a meta-analysis was conducted to determine the ergogenic effect of caffeine on endurance time-trial performance. Results 44 studies met the inclusion criteria and were included in the meta-analysis. Caffeine has a small but evident effect on endurance performance when taken in moderate doses (3-6 mg·kg −1 ) as well as an overall improvement following caffeine compared to placebo in mean power output (2.92 ± 2.18%; Effect Size = 0.22 ± 0.15) and time-trial completion time (2.26 ± 2.60%; Effect Size = 0.28 ± 0.12). However, differences in responses to caffeine ingestion have been shown, with two studies reporting slower time-trial performance while five studies reported lower mean power output during the timetrial. Caffeine can be used effectively as an ergogenic aid when taken in moderate doses, such as during sports when a small increase in endurance performance can lead to significant differences in placements as athletes are often separated by small margins.

Wake up and smell the coffee: caffeine supplementation and exercise performance—an umbrella review of 21 published meta-analyses

“…3 Given inconsistent evidence in the primary research that examined the effects of caffeine on exercise performance, several research groups explored this area using meta-analytical methods. [4][5][6][7][8][9][10][11][12][13][14][15] While these meta-analyses generally report ergogenic effects of caffeine on exercise performance, even adequately conducted meta-analyses tend to focus on the ergogenic effects of caffeine within just a single performance domain. As an illustration, Grgic and Pickering 10 only examined the effects of caffeine ingestion on isokinetic peak torque.…”

The Role of Genetics in Moderating the Inter-Individual Differences in the Ergogenicity of Caffeine

“…An increase in lipid mobilisation was hypothesised to increase glycogen sparing and thus, delayed fatigue during endurance exercise [ 3 , 4 ]. However, since then, other studies have shown that caffeine does not significantly increase lipid metabolism during exercise [ 9 , 10 , 11 , 12 , 13 ]. Evidence now indicates the ergogenicity of caffeine is most likely due to its effect as a potent adenosine receptor antagonist, whereby it blocks the actions of adenosine primarily in the brain [ 9 , 14 , 15 ].…”

Infographic. Wake up and smell the coffee: caffeine supplementation and exercise performance

“…The included meta-analyses explored the effects of caffeine versus placebo on different exercise tasks, including aerobic endurance, muscle strength, muscle endurance, anaerobic power, jumping performance and exercise speed. Moderate-quality to high-quality systematic reviews that provided a moderate quality of evidence (assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria) support the ergogenic effects of caffeine on muscle endurance, muscle strength, anaerobic power and aerobic endurance 5–8. For other outcomes, namely, jumping performance and exercise speed, we found moderate-quality reviews that provided evidence categorised as of low or very low quality on the GRADE assessment.…”