With the 2012 Summer Olympics starting this week, reaching the top is on the minds of thousands of athletes from across the globe. But a new study published in the British Medical Journal shows that athletes can't count on sports drinks or special shoes to help them achieve their goals.
Peter Gill, a University of Alberta medical student now on a Rhodes Scholarship, was a part of this new study out of the University of Oxford where he is completing his PhD. The research involved looking at claims by sports drink and sportswear companies that their product helps to improve performance and avoid injury.
"The major results that we found in the research were that there was little sound evidence to support claims made by some of sport's biggest brands," said Gill. "It is 'virtually impossible for the public to make informed choices about the benefits and harms of advertised sports products,'" he said, quoting from the study.
The Oxford researchers searched for advertisements in general magazines, as well as sport and fitness magazines in the United Kingdom and the United States with claims related to sports performance or enhanced recovery. They then looked at the evidence behind performance-enhancing claims, which included obtaining full-text copies of all cited references, appraising the methods used in the research and determining the risk of bias.
"More than half of the websites that made performance claims did not provide any references," says Gill. "We were only able to critically appraise approximately half of the articles, and of these 74 articles, 84 per cent were judged to be at high risk of bias. Only three of the 74 studies were judged to be of high quality and at a low risk of bias."
The researchers looked at six common myths in sport:
· The colour of urine accurately reflects hydration.
· You should drink before you feel thirsty.
· Energy drinks with caffeine or other compounds improve sports performance.
· Carbohydrate and protein combinations improve post-workout performance and recovery.
· Branched amino acids improve performance or recovery after exercise.
· Compression garments improve performance or enhance recovery.
In short, those debunked in this study include: colour of urine (many factors are related to colouring), which is something athletes are told to keep an eye on; drinking before you feel thirsty (it may worsen performance); energy drinks with caffeine and other compounds (no benefit above and beyond the boost from caffeine); and carbohydrate and protein combinations post-workout (don't improve performance and recovery).
"The results are very surprising, as they question many of the claims made by advertisements for sports products," said Gill. "The current evidence is not sufficient to inform the public about the benefits and the harms of these products.
"The marketing of sports products has become a multibillion-dollar industry and the consumption of so-called energy drinks is increasing year on year, but research in this area has previously been labelled as methodologically poor," he said. "Many of the sports drinks contain high levels of sugar and there is concern their consumption may contribute to the increasing levels of obesity in children."
To view the BMJ articles, please click here.