Scientists have shown that high doses of caffeine directly increase muscle power and endurance during relatively low-intensity activities.
Scientists from Coventry University believe that the findings may lead to the use of caffeine in sport to improve performance.
Currently, caffeine is not considered as a banned substance at any concentration in blood or urine samples.
A member of the team, Jason Tallis, found that high doses of caffeine enhanced power output by 6 percent under both maximal and sub-maximal activities.
However, 70uM caffeine treatment increased endurance during sub-maximal activity, but significantly reduced endurance during maximal activity.
Scientists already know that ingestion of caffeine can increase athletic performance by stimulating the central nervous system.
"70 uM caffeine concentration is the absolute maximum that can normally achieved in the blood plasma of a human, however concentrations of 20-50 uM are not unusual in people with high caffeine intakes", explains Dr James.