Alex Hutchinson draws on the latest research to answer your fitness and workout questions
in this biweekly column on the science of sport.
Do I need fancy, expensive shoes to exercise in, or is it all hype?
It's true that the athletic-shoe industry produces some of the world's best hype. Kids everywhere have grown up believing Spike Lee's famous pitch for Nike's Air Jordans: "It's gotta be the shoes!"
Underlying the hype is an enormous amount of research into the biomechanics of foot motion. Everyone agrees that court sports - such as basketball, which demands sharp lateral motion - require shoes with strong ankle support. But many people don't realize that running shoes, too, have highly specialized features to compensate for the generally lousy biomechanics of our feet and legs - and different shoes are designed to compensate for the flaws of different foot types.
It's fairly clear that, for some people, these supershoes work. Jack Taunton, director of the Allan McGavin Sports Medicine Centre at the University of British Columbia and chief medical officer for the 2010 Olympic Winter Games, has used training clinics for the Vancouver Sun Run 10K race as a laboratory to study the training of thousands of runners over the past two decades.
Injuries still occur, he says, "but as we've seen shoes get better over the years, they're less often found to be the main factor."
One correlation that Dr. Taunton and his colleagues found is that men whose shoes were more than four months old were more likely to get injured. For women, the effect was only noticeable once their shoes were more than six months old, presumably because men are generally heavier and thus compress the shoe cushioning more quickly.
That doesn't mean that shoe technologies are as revolutionary as the shoe companies say. A study by researchers at the University of Texas at El Paso, to be published in the British Journal of Sports Medicine, found no difference in the effects of air, gel and spring-type cushioning on the performance of running shoes worn for over 300 kilometres.
Foot type, on the other hand, is a crucial factor in shoe choice. The ideal running stride involves landing on the outside of the heel, then rolling inward before taking off from the toe, a shock-absorbing motion known as pronation. About 40 per cent of people pronate too much and require motion-control shoes to prevent injury, Dr. Taunton says. Ten per cent don't pronate enough and require cushioned shoes for extra shock absorption. The rest require neutral shoes that balance cushioning and motion control.
At least, that's the theory - but there are plenty of critics. In another paper in the same journal, published earlier this year, Australian researchers conducted a literature review and concluded that no controlled clinical trials have ever demonstrated that modern running shoes reduce injury rates.
"Shoe researchers and manufacturers will try [to]bamboozle you with the results of hundreds of biomechanical studies," the study's lead author, Craig Richards, said in an e-mail. While these studies tell you how your stride is affected by the shoe, "they cannot currently tell you what this means for either the injury risk or performance of the wearer."
For now, it's safe to say that if you're exercising without pain, you should stick with what's working.
If you do start having trouble anywhere in the feet, legs or lower back, head to a specialty running store where the staff have been trained to determine your foot type by watching you run. There's no need to spring for the fanciest shoes in the store, but it's worth having a shoe designed with your foot in mind.
Alex Hutchinson is a former member of Canada's long-distance running team and has a PhD in physics.Report Typo/Error