Why Is Marathon Pacing So Difficult?
There is a growing body of evidence that pacing in distance running events is governed by a brain-based mechanism that has been referred to as teleoanticipation. This mechanism continuously calculates the maximum pace that the runner can sustain through the remainder of a race without a catastrophic loss of homeostasis (such as overheating) occurring. The factors that are used in this calculation include conscious knowledge of the distance remaining, physiological “set points” such as the maximum allowable core body temperature, and feedback signals sent from the muscles and other organs to the brain. The results of the calculation are adjustments to the level of muscle activation (hence the runner’s pace) and perceptions of fatigue that serve to limit the intensity of exercise to the maximum level that will not cause serious self-harm.
Running experience plays a key role in calibrating this mechanism. When children do their first one-mile fun run, they invariably start at a full sprint and bonk within a few hundred yards. But this mistake teaches them to pace themselves much better in their next fun run. This process continues as long as the runner stays in the sport, so that eventually almost every runner develops a highly refined capacity to pace himself in races — except, perhaps, in marathons.
Research on pacing has shown that an evenly paced effort — often with a short finishing “kick” — produces the fastest finishing times in running, cycling, and other endurance time trials of more than a couple minutes’ duration. Experienced runners naturally tend to follow this pacing strategy in most races, which is manifest in the vast majority of world records set at every track race distance from 1,500 to 10,000 meters.
RELATED: Is Your Goal Pace Too Easy?
It stands to reason, however, that there is a limit to the computational power of the teleoanticipation mechanism. As race distances increase, there must come a point at which this mechanism can no longer comprehend the distance well enough to make an accurate calculation. There is clear evidence that almost all runners slow down in 100K ultramarathons. The highest finishers slow down least, but they’re still far from negative split territory. So it would seem that the limits of accurate teleoanticipation lie somewhere between 10,000 meters and 100 kilometers.
My research suggests that it’s on the short side of 26.2 miles for most runners, yet both the men’s and women’s marathon world records were run as negative splits. At the 2007 Frankfurt Marathon, Haile Gebrselassie ran the first half in 1:02:29 and the last half in 1:01:57. And at the 2003 London Marathon, Paula Radcliffe ran the first half in 1:08:02 and the second half in 1:07:23. Therefore it seems that the marathon is within the teleoanticipatory limits of the very fastest — or at least the best-trained — runners. It’s probably the best-trained runners, because there is no indication that pacing ability is linked to running talent, while there is abundant evidence that it is linked to running experience.