Infographic. Wake up and smell the coffee: caffeine supplementation and exercise performance

Caffeine has been used as a performance-enhancing aid by athletes for many years. The first known study to explore the effects of caffeine ingestion on exercise performance dates back to 1907.1 Until recently, however, findings on this topic remained equivocal, despite a large number of published studies over the last 30 to 40 years.2 There are many possible reasons for the discrepant results between these studies, but one likely issue could be a common use of relatively small samples. To reconcile the equivocal evidence on this topic and overcome the low statistical power of individual studies, researchers have started to use meta-analytical methods. Meta-analysis is a statistical method that allows pooling of results from studies that address a similar research question.3 Given that meta-analytical …