Drinking a cup of coffee before exercise could help increase the amount of weight loss during the activity, say researchers in Australia.
A team at the Australian Institute of Sport in Canberra also found that athletes who had a relatively small intake of caffeine before exercise, could continue for up to 30 per cent longer than those who had not taken the stimulant and perform up to 3.5 per cent beyond their normal capacity.
The researchers suggested that substances in caffeine triggered the muscles to use fat to fuel exercise instead of the usual carbohydrate stores.
Caffeine has long been used to enhance sports performance and is included in numerous sports supplements and energy drinks.
In tests the researchers found that drinking a cola drink or coffee helped cyclists keep going longer than those who were given water.
Other studies have found that caffeine taken during exercise can delay the onset of fatigue by up to 60 per cent.