The widespread belief that caffeine enhances physical performance and endurance during exercise appears to be yet another myth proven wrong. To test the placebo effect of caffeine, researchers conducted a study where moderately trained male athletes were given caffeine or placebo prior to exercise tests. During each test, the researchers measured the participants’ heart rates, perceived levels of exertion and blood lactate levels, which is an indicator of exercise intensity and its effect on the body with regards to oxygen exchange.

The study results showed a significant placebo effect with caffeine consumption on short-term, high intensity exercise. There were no differences in heart rates, fatigue levels or blood lactate levels among all participants regardless of whether they consumed caffeine or placebo. The group that performed the worst was told they received a placebo and really did in fact consume a placebo, while performance was enhanced when participants were told they had caffeine and did receive it. Keep in mind that this was a small study (only 12 athletes enrolled) and the results may be skewed since the researchers did not take into account how much the participants consume caffeine on a regular basis, which may have possibly affected how the athletes performed. In addition, the findings in this study are contrary to pro-caffeine findings by other studies.

The takeaway message from this study is that the placebo effect of believing that people consumed something “enhancing” was enough to increase exercise performance, which reiterates the power of mentality. Believing is…everything?