Caffeine gave team-sport athletes a small edge in sprints and jumps, and little else, in a review of 97 trials

Caffeine is one of the most common aids in team sport. Plenty of clubs hand it out before matches. A new review asks what it actually changes for players, and the answer is narrower than its reputation.

The study, a systematic review and meta-analysis led by researchers at Hangzhou Normal University in China, was published on November 5 in Frontiers in Nutrition. The protocol was registered in advance on the Open Science Framework.

The setup

The team searched four major research databases up to April 29, 2026 for randomized crossover trials in team-sport athletes. In a crossover trial, the same athletes do the same tests twice, once after taking caffeine and once after a look-alike placebo, so each person is compared with themselves.

They found 97 studies with 1,516 athletes: 1,018 men, 434 women, and 64 whose sex wasn't reported. Soccer was the most studied sport, followed by basketball and rugby. The outcomes fell into four groups: sport-specific skills, physical performance tests, performance during real or simulated matches, and how tired the athletes said they felt.

Effects are reported as standardized effect sizes. As a rough guide, values around 0.2 are usually described as small and around 0.5 as moderate.

What caffeine changed

Caffeine had small effects on a set of short, explosive efforts. Sprint times improved, with an effect size of 0.34, and so did repeated sprints and agility, also at 0.34. Single jumps improved by 0.29, power output by 0.33 and muscle strength by 0.20. Skills using the arms and hands, such as throwing or shooting, improved by 0.25, and physical output during match play by 0.23.

The confidence behind these numbers varied. Using a standard grading system, the authors rated the evidence for sprint times as high certainty. Most of the other gains were rated moderate, and agility was rated low.

What it didn't change

Several outcomes showed no clear effect when pooled. These included skills using the legs and feet, technical performance during matches, endurance tests, and how tired players felt. The evidence for that last one was rated very low certainty.

The authors also looked at whether dose, form, sex or level of play made a difference. Some subgroups showed effects at lower doses or in specific formats such as capsules or gum, but none of these differences held up in formal tests after correcting for multiple comparisons. The authors describe those subgroup results as exploratory.

What to keep in mind

This is a review of studies in trained athletes doing performance tests, often in a lab or a simulated game. It says nothing about everyday caffeine use, and it is not a recommendation to take caffeine or any particular amount. The effects are small, and much of the evidence was marked down for risk of bias in the original studies. Men also outnumbered women more than two to one. The work was funded by student research programs in Zhejiang and a Hangzhou research program, and the authors declared no competing interests.

Where Soma fits

The useful part of this review is its honesty about size: real effects, but modest ones, on some things and not others. That is a good way to think about any single habit. Soma doesn't measure caffeine or sprint speed. The Soma app, not yet available, will read the heart, sleep and activity data that your phone and watch already store in Apple Health, so you can look at your own patterns over weeks instead of relying on one study's average.

Sources, as of November 7, 2026: Zhou, Li, Chen, Dong, Wang, Wang, Cao, Jin and Wang, "Effects of acute caffeine ingestion on sport-specific skills, physical performance, on-field competition performance, and perceived fatigue in team sport athletes: a systematic review and meta-analysis," Frontiers in Nutrition, doi 10.3389/fnut.2026.1943680, published under CC BY 4.0. This post describes research and isn't medical advice.