For those of you running tomorrow's Dubai Marathon, the training miles will already have been run. As the countdown to race day begins, your mind will turn to last-minute preparations: what to eat and drink and, perhaps most importantly, what to wear on your feet. Choosing a pair of trainers used to be a simple shopping decision. But selecting the right pair of shoes from the thousands of styles on sale is now a bewildering task. What's more, say sport scientists and physiotherapists who have been analysing the burgeoning trainer market, make the wrong decision and you could pay the price in the form of leg, back or foot pain that will prevent you from running a step.
Running is a cheap and effective way to keep healthy, but there is no denying that it is a high-impact activity. Each time your foot strikes the ground, a shock equivalent to three times your body weight reverberates from the feet, through the legs and into the spine. Wear inappropriate shoes and you risk suffering shin splints, knee and back pain and tendonitis. Despite advances in shoe technology and manufacturers' claims that their products have advanced features to protect the injury-prone, the latest studies suggest that anything between 40-70 per cent of runners are hurt doing their favourite activity every year. Often, say the experts, running shoes are partly or entirely to blame.
"It's so easy just to pick up a pair or running shoes and be wooed into buying them because of the marketing slogans or the claims that are made about them," says Sammy Margo, a spokesperson for the Chartered Society of Physiotherapists. "What may be good for one person could injure another. It's vital to seek out professional advice when buying any kind of shoe to exercise in but you should also think about what you want them for." Today's trainers offer a range of special features such as anti-pronation devices (designed to prevent feet from rolling inward too much), super-cushioning and extra stability to correct gait problems and awkward running styles.
But in a report, published in the British Journal of Sports Medicine last year, Dr Craig Richards from the University of Newcastle in Australia analysed a range of so-called "prescription" running shoes and found not a scrap of evidence to show the shoes helped prevent or improve injuries. "We searched for studies which compared adult runners who wore modern running shoes, with elevated cushioned heels and pronation-control features tailored to foot type, with those running in bare feet," Richards says. "We restricted our searches to studies which measured the impact of wearing these shoes on a real-world outcomes such as distance running performance, musculoskeletal injury rates, osteoarthritis risk, enjoyment of running or overall health and quality of life. We failed to find a single published study."
So how do you choose a shoe that is going to help rather than hinder performance? Spending top dollar certainly isn't the answer. Some researchers have found that runners who wear more expensive shoes are twice as likely to get injured than those who opt for cheaper designs. In one recent study, Professor Rami Abboud, an orthopaedic surgeon at the University of Dundee's Ninewells Hospital and Medical School, found that a £40 (Dh215) pair of running shoes was as effective, in terms of cushioning and overall comfort, as a pair costing twice as much. "Our advice when shopping for trainers is to try them on, decide which ones seem to fit the best and don't judge them by the price tag," Abboud says. "Expensive trainers may seem to offer more, but you may not need more. In fact, the added extras can cause problems if they don't suit your feet."
Louise Sutton, the head of the Carnegie Centre for Sports Performance and Wellbeing at Leeds Metropolitan University, recommends a shoe with a reasonable amount of cushioning, but not too much. "Highly cushioned trainers are only necessary for people with high arches who need help absorbing impact when they land," she says. "For the rest of us, too much cushioning in the sole of a shoe can literally cause us to wobble out of control when we run, potentially causing strains and injuries." Never wear cross trainers to run in as they provide too little support for the forward to backward motion of running, Sutton says. "And if you are a relative newcomer to the sport, don't opt for any anti-pronation or stability features as they could lead to more problems than they solve."
Wearing trainers that are past their best is another way to raise the likelihood of injury. "Cushioning in the midsole diminishes with age and trainers are literally worn out after 500-800km of wear and tear," says Margo. "Look at the soles to see if there is any tread left - if the pattern has worn away, then there is little protection. If the white midsole looks flattened, the trainers are worn out. Also, take out the removable insole and check whether it has worn away at the ball of the foot or the heel. All of these are signs that you need a new pair."
Experts even suggest that periodically ditching trainers altogether is no bad thing. Emerging research into the benefits of barefoot running are proving that it produces fewer injuries than trainer wearing. In Australia, physiotherapists showed how the extra weight of trainers impeded performance far more than a few excess pounds around the midriff. Ease yourself into it gently by going shoe-free at home until you can manage 30 minutes at a time - it can take a while to develop thickening of the skin and for muscles and ligaments to adapt, but you can then progress to gentle barefoot workouts on springy grass or sand.
Ironically, many sport shoe manufacturers are now catching onto the concept by designing trainers that precisely mimic the form and movement of the human foot. For Dr Richards, shoes such as Dunlop Volleys - a basic canvas plimsoll with a thin PVC sole, thin foam inner sole, no arch support and a very slight heel elevation that have sold in their millions over the last 50 years - are as good as any. Even wearing them in a mini triathlon, Dr Richards says his "gait felt natural and very similar to going barefoot". Could the flashy trainer have had its day?