Is there an ideal running stride, and can I learn it?
You may think running has more in common with day-to-day functions like breathing and eating than with more technical sports like golf or swimming: As kids, we learn how to run with no special instruction, just as our ancestors have for millennia. The result?
"Most people run very badly," says Blaise Dubois, a Quebec City physiotherapist whose multi-day course on the prevention of running injuries has been drawing sellout crowds of health professionals, coaches and running enthusiasts around the world.
Over the past decade, a thriving industry has emerged based on the premise that we need to be taught to run properly, just as we need lessons on how to swing a golf club. As a result, researchers have been studying the complex interplay between such factors as stride length, posture and which part of the foot touches the ground first.
Evidence for the existence of an "ideal" running stride remains mixed at best - but it's clear that, while there may be no single correct answer, there are some definite wrong answers that can be addressed with simple fixes.
A running stride can be "bad" in two ways: It wastes energy or it leaves you more vulnerable to injury. In Mr. Dubois's work with members of the Canadian national track team and other elite athletes, efficiency is key. But for the vast majority of the patients in his clinic, the primary goal is to enable them to run injury-free.
In principle, we're perfectly capable of learning an efficient stride by just doing it, Mr. Dubois says. The ideal stride is the one each of us would have if we spent our childhood running around barefoot - like many kids do in, say, Kenya. "Just by running a lot, you become more efficient and develop intrinsic protection against injury," he says.
The problem is that few Canadians grow up that way any more. So when we start running as adults, we're prone to taking long, slow steps instead of short, quick ones, and landing with the foot too far in front of the body. The resulting heel-first crash landing produces higher forces in the knee and hip joints than experienced by lithe Kenyan barefooters. This is where the injury epidemic comes in - by some estimates, 80 per cent of new runners fall victim.
Modern running shoes are a big part of the problem, Mr. Dubois believes, partly because they block the feedback you would normally get through the bottom of the foot. It's almost impossible to keep over-striding and thudding onto your heels in bare feet or thin-soled shoes, simply because it hurts too much. (Try this at home!) It's no coincidence, then, that in the past 30 years the typical number of steps per minute taken by joggers has declined to 150 from between 170 and 190, paralleling the rise of bigger, bulkier shoes.
One option, then, is to try minimalist shoes with no heel lift. A University of Wisconsin study published last year tested another approach. Simply counting the number of steps you take, then consciously increasing it by 5 to 10 per cent (using a metronome, initially) produced many of the same changes you'd see by taking your shoes off. Thanks to the shorter, quicker strides, runners in the study absorbed less force in their knee and hip joints.
"It's a way of having your cake and eating it too," says Michael Ryan, a postdoctoral researcher who co-authored the paper. "You can run in shoes but still get some of the same benefits."
There was a trade-off, though: Shorter strides led to an increase in forces on the ankle. Mr. Dubois sees the same thing, noting that runners switching to barefoot or minimalist shoes are prone to problems in the calf muscles, Achilles tendon and ball of the foot.
That's the fate that befell subjects in a 2004 study of the Pose Method, which teaches runners to adopt an S-shaped pose as each foot hits the ground. The study found that a one-week teaching period did indeed lead to shorter strides and lower loads on knee joints. But within a few weeks after the study ended, 14 of the 20 subjects had developed calf or Achilles tendon problems, one of the researchers later revealed.
The bottom line is, you have to be patient. "Whenever you change something there's a short-term risk," Mr. Dubois acknowledges. But if you progress slowly and give your muscles and tendons time to adapt, he says, the long-term payoff of a shorter, quicker stride may be injury-free and efficient running.
Alex Hutchinson blogs about research on exercise at sweatscience.com. His new book, Which Comes First, Cardio or Weights?, will be published in May.
Cruise control for runners
Each of us has a unique combination of stride length and step frequency that feels most comfortable at any given speed. While some running-injury specialists recommend changing this relationship, Max Donelan and Mark Snaterse of Simon Fraser University are taking advantage of it with a newly developed "cruise control" system for runners.
Combining a highly accurate GPS to measure speed with a metronome that beeps at the appropriate cadence, the system allows runners to lock in at a preset pace - and if they stray, it gently nudges them back by increasing or decreasing their step frequency. The researchers have applied for a patent and hope to commercialize the system.