CAFFEINE AND SHORT-TERM EXERCISE PERFORMANCE
Research suggests that caffeine ingestion improves performance during short-term exercise
lasting approximately 5 minutes at 90 to 100 percent of maximal oxygen uptake in the laboratory. This exercise intensity requires maximal provision of energy from both aerobic (oxygen requiring) and anaerobic (non-oxygen) sources. It is unknown if this finding applies to race situations. The reasons for the performance improvement may be a direct positive effect of caffeine on muscle anaerobic energy provision and contraction or a central nervous component related to the sensation of effort. Caffeine ingestion does not appear to improve sprint performance, but additional well-controlled laboratory and field studies are required to confirm this conclusion. Sprinting is defined as exercise that can be maintained from a few seconds to 90 seconds where most of the required energy is derived from anaerobic metabolism.