The Athens Olympic Marathon in 2004 was meant to be Paula Radcliffe's race. Since her marathon debut in London in 2002 the British world record holder had never been defeated over the distance. Certainly the Kenyans, Ethiopians and Japanese presented an outside threat, but Radcliffe was the bookies' favourite going into the race.
Leading the field: Paula Radcliffe
It was a different story for America's top runner Deena Kastor. She didn't even figure in the predicted top five, but she should have. Both runners had trained hard and were mentally prepared for the challenge but the pair adopted completely different approaches to race strategies.
Radcliffe set the pace, as she had in all her previous marathons, daring the other runners to keep up with her. Kastor had a different approach though. She'd decided, with her coach, that the Athens course required a steady first half with a bigger effort in the second, as the course became hillier but conditions became cooler. Her perfectly-paced effort saw her run a conservative race to pick off runners in the closing stages and finished strongly to win a surprising bronze medal. It was the USA's first Olympic Marathon medal since Joan Benoit Samuelson won gold at the inaugural women's marathon in 1984.
Kastor's tactical decision to run a classic negative split earned her a place on the podium while Radcliffe sat on the side of the road with her head in her hands, proving beyond doubt that perfect pacing will always reap rewards, even in conditions that defeat the toughest of athletes.
Split the difference
Running a negative split, as Kastor chose to in Athens, is one of the most popular pacing strategies in racing. It simply means that you run the second half of the race faster than the first, which is a safe strategy if you're racing yourself and the clock rather than other runners. Steve Smythe, a coach and marathon runner, suggests easing into the pace that you intend to run at. "Try to reach the halfway point in roughly half of your goal time," he says. "Speed up a little after that until you reach the last 10 per cent of the race. Then you should give it your all."
Another way to approach the negative split is that adopted by many elite runners. They run the first half of a race conservatively before attacking the second half as the real race. Mike Gratton, a coach and former London Marathon winner, has tried using this two-races-in-one approach, as well as attacking straight from the gun. "Nearly every time I have gone for it from the start, I have blown up," he says. "During my best performances, such as my London Marathon win in 1982, I ran a calculated pace to the halfway mark then moved through the field."
While the negative split may be a favourite pacing strategy with coaches, it isn't the only approach. The positive split, which often relies on a fast start, is a riskier strategy, but there's increasing evidence that it can work too. Researchers in New Hampshire in the USA decided to find out how different pacing strategies affect race results. They asked 11 experienced female runners to run 5K on a treadmill to determine their average for the distance.
The runners were then asked to run 5K again, but tackling the first 1.63K at different speeds: once at the same split time as their average time, once three per cent faster, and once six per cent faster. The researchers discovered that eight out of the 11 women ran the fastest 5K when they started six per cent quicker, in other words they ran a positive split. Overall the fastest-start trial times were 13 seconds quicker than the three-per-cent-faster times, and 32 seconds faster than the even-pace trial times; results that would translate to a new personal best for many of us.
Other sports scientists have recorded similar findings, but stress that this strategy only works over shorter distances. "Some data suggests that starting fast enhances the transport of oxygen and resultant energy production, termed oxygen uptake kinetics," says Professor Greg Whyte of the Research Institute for Sport and Exercise Science, Liverpool John Moores University. This is particularly true of shorter races up to 5K but he warns that starting too fast might also lead to such a high rate of anaerobic metabolism – where the lungs cannot transport enough oxygen into the blood to keep up with the muscles' demands – that performance will be impaired.
Although the New Hampshire researchers asked their volunteers to complete more than 25 per cent of the 5K at a higher pace, even a shorter burst could produce good results since it often provides a mental boost. "If you can dominate in the early stages of a race, then settle into your normal pace once you've broken away from the opposition, you'll gain a psychological advantage," says Gratton. Smythe agrees, but issues a warning: "There is no harm starting quickly for a short period, say the first 800m in a 5K or first mile in a marathon," he says, "but you should settle into your goal race pace after that."