Players should be warned about the indiscriminate use of dietary supplements, but a few may have something to offer for some players. If energy intake is adequate to meet training and match demands, and a varied diet is chosen, the risk of vitamin and mineral deficiencies is very low, but not all players choose a varied diet. 5 If supplements are to be used, this must be a conscious decision based on evidence of efficacy and a low risk of adverse effects. Players should be protected from the use of supplements that may contain doping agents by using only those shown to be at low risk for contamination with prohibited substances. Supplements should be used only on the advice of a qualified sports nutrition professional or after consultation with a doctor.
Use of supplements during FIFA competitions
Eighty per cent of all athletes attending the 2000 Olympic Games in Sydney were found to be using some form of medication or supplements. Since the 1998 FIFA World Cup™ in France, team doctors have been required to record all medications and supplements used by their players during a FIFA competition. In this way, the rate of supplement and medication use during these tournaments has been recorded. High rates of supplement use have been demonstrated – with no real changes in their use being noted over the past decade. 6
The most widely used supplements in a football context are sports drinks, protein powders/bars and carbohydrate-rich recovery products. These can provide a convenient way to meet specific nutritional goals, but, with some planning and a little effort, most of these goals can also be met with normal foods.
- There is widespread use of creatine among athletes, especially those who are strength-trained. Creatine supplementation may improve performance in short intense exercise – and may also have a role in more prolonged endurance exercise involving repeated sprints. Athletes usually take a loading dose of creatine followed by daily supplementation, but the loading dose is not necessary.
- There is quite good evidence for a performance benefit in a variety of events lasting from one minute to ultra-endurance events. There are likely to be reasons for this, including an alteration in the perception of exertion. Performance benefits have been shown with relatively small doses (1-3mg/kg). To put this into context, an espresso has approximately 60-100mg caffeine.
- Probiotics may have a role in improving immunity. There is some science suggesting that the use of probiotics can reduce the risk of developing an upper respiratory infection and travellers’ diarrhoea. They are unlikely to do any harm and some players may benefit.