to go for your morning run? Try downing some coffee before your workout. A recent review published by the International Coffee Organization states that caffeine at levels found in one cup of coffee may be able to both reduce the sensation of fatigue as well as enhance exercise performance.
Caffeine’s effect appears to be applicable to a diverse variety of sports and exercises. The studies conducted have been wide ranging and have included well-trained athletes and relatively sedentary individuals of both sexes and different age groups.
The most comprehensive and recent review (Doherty and Smith 2004) looked at 39 published studies. Of these, 21 involved endurance exercise, 12 used short duration and high-intensity exercise and the remaining 6 used a graded exercise test. Including all these data, caffeine improved performance by 12.4%, relative to the placebo trials and this was shown to greatest effect in those who undertook exercise for a longer duration at any one time.
In many of these studies, where performance was improved by the ingestion of caffeine or drinking coffee, there was the also the additional benefit of an associated reduction in the sensation of fatigue.
There were also a number of studies involved in the review that show the beneficial effects of drinking coffee and/or ingesting caffeine before high intensity exercise. These include improved performance on a 1500 mile run and demonstrated that anaerobic power in a cycling test was improved by the ingestion of the equivalent of two cups (250mg) of caffeinated coffee. Cycling was also the sport studied more recently when caffeine (5mg/kg) was shown to improve performance in a high intensity cycling test. The beneficial effect has also been demonstrated in swimming trials. They showed that in a swimming test (2x100m), there was improved performance after ingestion of 250 mg of caffeine.
In a presentation at the International Coffee Organization, Professor Ron Maughan, head of the School of Sports and Exercise Science at Loughborough University and adviser on Sports Nutrition to the International Olympic Committee, said, “ Given the various initiatives aimed at promoting physical activity to improve health, anything that encourages participation by reducing the discomfort and fatigue most people feel when exercising, has enormous implications for improving public health.”
Most Effective Amount of Caffeine
Caffeine Content of Various Foodstuffs||
Foodstuff|| Serving size (mg)|| Caffeine content
Coffee*|| 150 ml|| 50-120|
Tea*|| 150 ml|| 15-50|
Chocolate Drink**|| 250 ml|| 10|
Milk Chocolate**|| 50g|| 40|
Caffeinated Soft Drinks|| 330 ml|| 40-100|
|(from Maughan 1999)
* Values for coffee and tea vary widely depending on the source and method of preparation.
** In addition to caffeine, chocolate contains theobromine, which has an insignificant effect compared to caffeine.
Recent studies used small amounts of caffeine (1-2mg/kg), that were found to be effective in improving exercise performance significantly. The smaller amounts, as little as 90mg caffeine, are not associated with any unwanted side effects.
The diuretic effect of caffeine is often over stressed, particularly in situations where dehydration is a major issue. This is of particular importance to those taking part in competitions held in hot, humid climates. Athletes competing in these conditions are often advised to increase their fluid intake but also to avoid tea and coffee because of their mild diuretic effect. Current research, however, shows that, not only is this mild diuretic effect insignificant during exercise, but the negative effects caused by cutting such drinks from the diet may be more damaging. Conclusions from published studies show intakes of less than 300mg caffeine a day will not affect levels of body’s fluids.
Given the various initiatives aimed at promoting physical activity to improve health, anything that encourages participation by reducing the discomfort and fatigue most people feel when exercising has enormous potential implications for improving public health. Caffeine, in the form of coffee or as a pure ingredient, may have that ability.
Caffeine is part of the naturally occurring group of stimulants found in leaves, nuts and seeds of a number of plants. Common dietary sources include coffee, tea, chocolate and a variety of soft drinks and sports drinks.
The International Coffee Organization is an intergovernmental organization created under the auspices of the United Nations to serve the international coffee community. For more information about the Positively Coffee Program, visit: www.positivelycoffee.org.