A study published in September 2026 in Medicine & Science in Sports & Exercise found that taking caffeine one hour before cycling can help maintain sprint performance for up to three and a half hours. Previously, it was believed that caffeine’s effects would mainly last during the first hour, when its concentration in the blood is highest. However, the study suggests that caffeine might support performance throughout a long training session or a full day of competition. Twelve volunteers took part in the study, which involved cycling three times over a period of three and a half hours. The test included thirteen young adults, with twelve completing the final analysis. One participant withdrew due to symptoms linked to the caffeine product. The remaining participants, eight men and four women with an average age of 24, consumed 5.5 milligrams of caffeine per kilogram of body weight, which is about 385 milligrams for someone weighing 70 kilograms. A placebo containing glucose was used for comparison in a double-blind trial. Three sets of sprints were performed at 60, 120, and 180 minutes after taking the caffeine or placebo. Each sprint series involved five minutes of moderate cycling followed by six five-second sprints at maximum effort. The average power output increased by 0.5%, 2.4%, and 1.6% across the three sets. The total work done during the session was also higher compared to the placebo group. However, both caffeine and the placebo showed the same decrease in power within each set, meaning the study couldn’t confirm that caffeine reduces fatigue. The researchers suggested that the test might not have been intense enough to create a clear difference in fatigue levels. Blood tests showed that caffeine levels peak around the second hour and remain high until the end of the test. During the sprints, norepinephrine—a hormone released during stress—increased more under caffeine. This likely explains the extra power seen in the cyclists. Participants also reported feeling less effort and leg pain, even though their heart rates were higher. This suggests they were able to push harder with less discomfort. An unexpected finding was that carbon dioxide levels in the breath and blood flow in certain arteries decreased under caffeine. This is due to caffeine’s known effect of constricting blood vessels in the brain, which is a well-documented phenomenon. However, the researchers did not determine whether this effect is significant at high doses. The amount of caffeine used in the study was higher than that in a typical espresso, which contains 60 to 80 milligrams. The participants also consumed relatively little caffeine daily, and only four of them regularly drank it. Two of the volunteers reported adverse effects during the sessions with caffeine. The study did not measure sleep, and the researchers proposed a hypothesis—though it was not tested—that a morning dose of caffeine could maintain its benefits while preserving sleep. With only twelve participants, the results need to be replicated in larger studies before they can be considered a reliable training recommendation.