Caffeine’s athletic edge more evident in light beverage drinkers

Athletes that had become desensitised to caffeine through regular consumption found little improvement in sporting performance when asked to chew caffeinated chewing gum beforehand, said the team behind the study.

In contrast, athletes who rarely consumed caffeine were able to maintain athletic performance for a longer period of time in repeated sprint tests.

“In practical terms, ingestion of caffeinated chewing gum may be of value to team sport athletes, when rapid caffeine absorption and/or a low dose of caffeine is desirable, such as for pre-match or half-time ingestion,”​ said the authors, led by Dr Brendan Egan, associate professor of sport and exercise physiology at Dublin City University.

“While the ergogenic potential of caffeine is long-established, further work is still warranted in the context of team sport performance, particularly around timing and dose with this novel mode of delivery.”​

Caffeine mode of delivery​

The boosts in mental and physical effects offered by caffeine have long been known, especially in the athletic arena with particular gains found in endurance running or cycling.

However, effects on short-duration high intensity exercise performance to date have been mixed, with a large degree of variability based on the dose of caffeine administered.

While a body of evidence links habitual consumption and reduced sensitivity to the physiological effects of caffeine, the restoration of sensitivity upon withdrawal are not always observed in exercise performance settings.

Anhydrous caffeine in capsule or tablet form is typically used in sports performance studies, but caffeinated chewing gum offers a novel route of administration.

Caffeinated chewing gum may be of particular value when rapid caffeine absorption and/or low dosing is required.

Its ingestion results in earlier peak plasma caffeine concentrations, with 85% of caffeine released after 5 min of chewing and a relative bioavailability of 90%.

Study details ​

Dr Egan and his team enrolled 18 male team sport athletes to undergo a series of repeated sprints.

The athletes undertook 10 repeated sprints under conditions with and without two sticks of the caffeinated gum, equivalent to two strong cups of coffee.

Repeated sprint performance (RSP) appeared not to differ between the study group taking caffeine (caffeinated chewing gum; 200 milligrams (mg) caffeine) and the placebo group (non-caffeinated chewing gum).

However those athletes that had a low habitual caffeine consumption of less than 40 milligrams per day (mg/d) maintained their performance by 18% vs. placebo group in repeated sprint tests after ingesting caffeinated chewing gum.

Athletes with a moderate/high habitual caffeine consumers (more than 130 mg/day) did not benefit from caffeine as a performance aid as performance worsened over the course of the ten repeated sprints.

“The data suggest that a low dose of caffeine in the form of caffeinated chewing gum attenuates the sprint performance decrement during repeated sprint performance (RSP) by team sport athletes with low, but not moderate-to-high, habitual consumption of caffeine,” ​the study concluded.

Use of caffeinated chewing gum was interesting since the major site of caffeine absorption differs between the modes of delivery.

Caffeine absorption from chewing gum predominantly occurs through the buccal cavity. It is considered faster due to extensive vascularization and bypassing of intestinal and hepatic first-pass metabolism.

While the study’s finding’s supported the notion of an habituation effect, the team could not discount that this could be overcome by providing a larger acute dose of caffeine greater than the 2.5 mg/kg body mass (BM) provided in the study.

Source: International Journal of Sport Nutrition and Exercise Metabolism​
Published online ahead of print, doi: 10.1123/ijsnem.2017-0217​​
“Acute Ingestion of Caffeinated Chewing Gum Improves Repeated Sprint Performance of Team Sports Athletes With Low Habitual Caffeine Consumption.”​
Authors: Mark Evans, Peter Tierney, Nicola Gray, Greg Hawe, Maria Macken, Brendan Egan.