Alex Hutchinson draws on the latest research to answer your fitness and workout questions in this bi-weekly column on the science of sport.
The question How should I pace myself in a five-kilometre road race?
At the finish line of this Sunday's Around the Bay Road Race in Hamilton, which has 30-kilometre and five-kilometre courses, you'll see everything from the death march of those who went out too fast to the furious sprint of those who held back too long.
As the 114-year-old event kicks off the spring race season, getting the pacing right is, understandably, a big concern for road runners. After all, you don't want to waste all the training you've put in - and you certainly don't want to be the weak link that costs your company team a chance for glory at Harry's Spring Run-Off or the Bay Street Rat Race.
The usual advice, lifted straight from Aesop's Fables, is that slow and steady wins the race. This is by no means bad advice - and for beginners, it should be treated as gospel.
But for those who have already run several races and are looking to improve their time, a 2006 study from the University of New Hampshire suggests a higher risk, higher reward approach.
Exercise physiologist Robert Kenefick and his colleagues tested various pacing strategies for the most popular road race distance, five kilometres. They had test subjects - who were serious recreational runners but not elite athletes - run a series of races with the speed of the first mile (1.6 kilometres) carefully controlled, either at an even pace based on their best time, or 3 or 6 per cent faster.
To everyone's surprise, the fastest overall times came from the fastest opening mile, while the slowest races came from running an even pace. The researchers measured physiological variables such as oxygen use and heart rate while the runners ran, but they couldn't detect any difference between the paces.
"Either way, you're tired at the end," says Dr. Kenefick, who is now a U.S. Army research physiologist. "So if you go out too slow, you can't make that up at the end."
Strangely, that doesn't jibe with the experience of Canada's top 5,000-metre Olympic hopeful, Reid Coolsaet, whose fastest time of 13 minutes, 21.53 seconds was set with even splits and a slightly faster finish. And world records at 5K are usually set with each kilometre equal to or slightly faster than the one before.
But Olympians are different from you and me, Dr. Kenefick points out. Their training prepares them to sustain an effort extremely close to their maximum without stepping over the edge, a feat that less-experienced runners are unable to duplicate.
For most recreational runners, the study suggests that riding an adrenalin surge at the start could allow us to put a few seconds in the bank without having to pay double for them in the closing kilometres. It could be a wise investment when pride is on the line.
Alex Hutchinson is a former member of Canada's long-distance running team and has a PhD in physics.
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