What is it?

Following ingestion, caffeine is rapidly absorbed and transported to all body tissues and organs where it exerts a large variety of effects. The mechanisms underpinning these effects may vary between individuals and include both positive and negative responses. Evidence of the use of caffeine to enhance sports performance has been developed over more than a century of scientific testing, with robust evidence² now confirming the following:

• Small caffeine doses (e.g. 2-3 mg/kg (~200 mg)) are effective at improving performance, irrespective of whether the caffeine is ingested before and during (in the case of endurance tasks) exercise.
• The major benefits of this dose of caffeine on exercise capacity and performance appear to be achieved by central nervous system effects, specifically those involving antagonism of adenosine receptors. These effects reduce the perception of fatigue and allow optimal pacing and skill/work outcomes to be maintained for a longer period.
• In addition, caffeine increases the mobilisation of fats from adipose tissue and at the muscle cell, can change to muscle contractility. While these effects exist, they are less likely to explain the magnitude of performance changes observed in the current literature.
• Individuals vary in their response to caffeine intake. Although caffeine may enhance sports performance in most, some individuals are nonresponders and others may respond negatively to caffeine ingestions.
• Athletes should be made aware of the potential of these effects and practitioners should be encouraged to trial its use with athletes before use in major competitions.

Caffeine was removed from the World Anti-Doping Agency Prohibited List in 2004, allowing athletes who compete in WADA sanctioned sports to consume caffeine within their usual diets or for specific purposes of performance. This change was based on the recognition that caffeine enhanced performance at doses consistent with everyday use, and that monitoring caffeine intake via urinary caffeine concentration was not reliable. WADA continues to test urinary caffeine concentrations within its Monitoring Program to investigate patterns of misuse. Pure or highly concentrated caffeine can be potentially lethal and hence pose an acute risks to consumers.