Caffeine metabolites are associated with different forms of caffeine supplementation and with perceived exertion during endurance exercise

Effects of Caffeinated Chewing Gum on Exercise Performance and Physiological Responses: A Systematic Review

BACKGROUND

Caffeine intake in the form of chewing gum is characterized by rapid absorption and utilization.

OBJECTIVES

The purpose of this study was to investigate the effects of caffeinated chewing gum on exercise performance and physiological responses in a systematic review.

METHODS

All articles were searched using the PubMed and Scopus databases to include articles published up to June 2024, following the Preferred Reporting Items for Systematic Evaluation and Meta-Analysis (PRISMA) protocol.

RESULTS

Thirty-two studies were finally included. Most studies have found that pre-exercise caffeinated chewing gum supplementation is effective in improving endurance, repetitive sprinting, lower limb strength, and sport-specific performance, as well as lowering rating of perceived exertion (RPE) or fatigue index even with lower dosages of caffeine. Sympathetic activation may be one of the mechanisms by which caffeinated chewing gum affects athletic performance. No significant effect on energy metabolism indicators (blood glucose, blood lactate, free fatty acids) was found. In addition, two studies found that caffeinated chewing gum reduced or maintained cortisol levels and increased testosterone levels. However, caffeinated chewing gum intake does not have an impact on catecholamines and β-endorphins. There have been inconsistent results for explosive performance, agility performance, and pain perception. Only a few studies have examined balance performance. In conclusion, a low dose of caffeine (100-300 mg or 2-4 mg/kg) in the form of chewing gum is rapidly absorbed and utilized, positively impacting most exercise and physiological performance.

CONCLUSIONS

Future studies should also consider the performance variables of agility, pain perception, and explosive performance to gain a more comprehensive understanding of the effects of caffeinated chewing gum on sympathetic activation and exercise performance.

Caffeine gum improves 5 km running performance in recreational runners completing parkrun events

PURPOSE

The purpose of this study was to determine whether caffeine gum improves the performance of recreational runners completing parkruns (weekly, 5 km, mass participant running events).

METHODS

Thirty-six recreational runners (M = 31, F = 5; age 33.7 ± 10.7 y; BMI 23.1 ± 2.4 kg/m2) capable of running 5 km in < 25 min were recruited to a study at the Sheffield Hallam parkrun, UK. Runners were block randomized into one of three double-blind, placebo-controlled, cross-over intervention trials with caffeine gum as the treatment (n = 6 per intervention trial) or into one of three non-intervention trials that ran concurrently with the intervention trials (n = 6 per non-intervention trial). Changes in conditions across different parkruns were adjusted for using data from the non-intervention trials. Runners in the randomized cross-over intervention trials chewed gum supplying 300 mg of caffeine or a placebo gum for 5 min, starting 30 min before each parkrun.

RESULTS

Caffeine gum improved 5 km parkrun performance by a mean of 17.28 s (95% CI 4.19, 30.37; P = 0.01). Adjustment for environmental conditions using data from the non-intervention trials attenuated the statistical significance (P = 0.04). Caffeine gum also decreased RPE by 1.21 (95% CI 0.30, 2.13; P = 0·01) units relative to placebo.

CONCLUSIONS

A 300 mg dose of caffeine supplied in chewing gum improved the performance of recreational runners completing 5 km parkruns by an average of 17 s.

TRIAL REGISTRATION

The study was registered at ClinicalTrials.gov: NCT02473575 before recruitment commenced.