The Australian Institute of Sport (AIS) has recognised caffeine as a 'group A' supplement meaning there is strong evidence for its performance-enhancing effects in sport. Specifically, robust evidence confirms that caffeine may reduce the perception of fatigue; allow for optimal pacing during exercise and enhance endurance.
Studies suggest a dose-response relationship of caffeine up to 200mg, suggesting that doses above this threshold may not add benefit, but might increase the risk of adverse effects. While the caffeine content of coffee is variable, a strong (double-shot) espresso might contain 200mg of caffeine. The benefits of caffeine occur very soon after intake, and possibly before maximal blood concentration is achieved (which occurs within 60mins).
Performance may be enhanced when used for various types of exercise including:
- Single efforts involving strength and power
- Endurance sports (>60mins)
- Brief high intensity sports (1-60mins)
- Team and intermittent sports (requiring work rate pacing, skill and concentration)
For reference:
AIS Summary on Caffeine