It is now becoming apparent that within a balanced diet there are foods that contain specific bioactive components that can be beneficial during exercise. These components can be extracted from those food sources (or synthesized chemically) and can be taken to specifically improve performance during, and recovery after, exercise. This is the basis of the sports performance supplement industry. Unfortunately most sports supplements that are promoted as having a positive effect on performance have no proof of effectiveness.
There are however, a small number of nutritional supplements that have been shown to be effective as enhancers of sports performance and recovery. These include:
Caffeine. Caffeine stimulates the central nervous system, increasing alertness and endurance, and delaying tiredness. Research shows that 1 – 3mg of caffeine per kg of body weight taken before or during exercise has a positive effect on alertness and performance. For an 80 kg person this amount of caffeine is approximately equivalent to the amount of caffeine in one cup of coffee.
Protein. Research has shown that taking protein shortly after intense exercise can help build and repair muscles damaged during the exercise. Protein supplements have been shown to be no better than protein rich foods, but protein supplements allow an easy way to consume a controlled and measured amount of protein. Typically taking 10 – 20 grams immediately after exercise has been shown to be beneficial.
Carbohydrates. Like protein carbohydrates are readily consumed as part of a normal healthy diet, however supplementation during exercise with carbohydrates that are rapidly converted to energy can be beneficial to performance and perception of effort. Supplements are mostly in the format of conveniently consumed drinks, sports bars or gels containing glucose and fructose. Carbohydrate supplementation is only of any real benefit when the duration of the exercise is over 60 minutes, and the recommended consumption rate is 30 – 90 grams per hour depending on the intensity of the exercise.
Creatine. Creatine occurs naturally in muscle and as such is consumed as a consequence of eating meat and fish. Taking sports creatine supplements has been shown to increase muscle mass and improve performance in sports where short bursts (up to 30 seconds) of intense effort are important, e.g. sprinting and weight lifting. Creatine does not provide benefits for longer endurance sports such as long distance running, swimming or cycling.
Berries. There is increasing evidence that supports the use of specific nutritionial bioactives, particularly those found in berries such as blackcurrants, to improve performance during, and recovery after, exercise. Blackcurrants are particularly effective for increasing performance in sports and exercise.