Science of Running

Better breathing

The basic idea seems pretty obvious: if running makes us out of breath, then we should train our breathing muscles in order to run faster. That’s the rationale behind a series of handheld gadgets like the “PowerBreathe” that train the diaphragm and chest wall muscles. Breathing through the device 30 times, twice a day, the company claims, is like lifting dumbbells for the respiratory muscles. This should benefit everyone from asthmatics to actors and singers, and help improve athletic performance. Somehow, though, the idea has never really caught on among runners, though there have been a few reports of elite Canadian runners trying the devices out.

A new study by researchers in New Zealand and the United Kingdom directly tests the effect of “inspiratory muscle training” (IMT) on 5K race performance, with some intriguing results. The IMT group didn’t improve any of the standard physiological measure of performance like VO2 Max (a measure of how much oxygen the body can process), but they did improve their 5K time by a couple of percent more than the control group. And the perceived exertion of the IMT group was lower during their running workouts. One possible explanation: training your breathing muscles helps you get used to being out of breath – so in the middle of a race, when you’re gasping for air, your brain is less likely to panic and send the “slow down!” signal to your muscles. As the researchers put it, the benefit of IMT may be “a temporary feature of altered perception” rather than “a sustained physiological adaptation.” But more research is needed to figure out whether that’s true.

Aging athletes

It’s probably the fastest growing topic in sports science these days: what are the risks and benefits of exercise for aging baby boomers? The Clinical Journal of Sports Medicine devoted its most recent issue to an in-depth look at some of the key issues, and drew the general conclusion that “there are very few contraindications to exercise in the elderly.” Among the studies was a comparison of muscle loss in aging athletes and sedentary people. After the age of about 50, we begin losing muscle fibres, whether we’re athletes or not – however, those who continue to exercise can compensate to some degree by making the remaining fibres bigger. It’s clear, though, that the “use it or lose it” dictum applies: even world-class athletes eventually regressed to sedentary values if they didn’t continue to exercise.

Another paper in the special issue, by McMaster University medical researcher Mark Tarnopolsky, examined the nutritional needs of aging athletes. Researchers know that the way the body stores and uses energy from food does change as we get older. However, studies so far suggest that older athletes should continue to follow the advice given to their younger peers. In particular, it’s crucial to ingest some protein and carbohydrate very soon after workouts in order to recover quickly and get stronger. One caveat is that, since older athletes are inevitably unable to sustain the extreme intensity and volume of exercise they might have done when they were younger, they will likely need less protein as a result.

It’s not the shoes

It can be difficult to keep up with all the different shoe technologies out there – springs, gels, air, and so on. Fortunately, a new study from researchers at the University of Texas at El Paso suggests that you don’t really need to worry about it. The goal of the study was to find out how runners’ strides changed as shoes gradually wore out. They tested the hip, knee and ankle angles, as well as the forces exerted by each footstrike, in a group of runners with new shoes, and again after the runners had run more than 300 kilometres in the shoes. Not surprisingly, the runners’ stride patterns changed as the cushioning in the shoes wore out. But the most interesting result was an unexpected bonus: the researchers had divided their subjects into three groups, corresponding to three different shoes from popular manufacturers (an air, a gel, and a spring). They didn’t observe any differences between those three groups, which suggests, they wrote, that “runners should choose shoes for reasons other than cushioning technology.”

Asthma inhaler inquiry

Exercise-induced asthma (EIA) is a problem for somewhere between four and 20 per cent of the population, often triggered by cold, dry air in the winter or pollution- and allergen-filled air in the summer. For reasons that aren’t well understood, elite endurance athletes are particularly susceptible to EIA, with a prevalence of up to 50 per cent in sports such as cross-country skiing. As a result, it’s not uncommon to see athletes using inhalers before big races – and that has led to the suspicion that some athletes are getting diagnosed with EIA just so they’ll be allowed to use the medication. For example, U.S. marathoner Mebrahtom Keflezighi was reportedly diagnosed for the first time after he arrived in Athens for the 2004 Olympic Games – just a few days before he won a surprise silver medal.

“There’s a big myth that these inhalers will somehow ‘open up the lungs’ and boost performance,” says Kenneth Rundell, an exercise physiologist at Marywood University in Pennsylvania. “But the scientific data don’t support that.” Several studies have failed to find any performance benefit from short-term use of these medications. Now, in the December 2008 issue of the British Journal of Sports Medicine, Dutch researchers are reporting that even a four-week program of anti-asthma corticosteroids doesn’t produce any measurable performance gain for healthy athletes. That doesn’t mean that the medications aren’t important for those who need them, but it does mean you should only use them if you’ve been properly diagnosed with a lung-function test administered by a doctor.