Running at max capacity

This new research confirms that the also-rans are working every bit as hard as the winners

A popular maxim among runners is that ‘back-of-the-pack’ individuals work just as hard as the front-runners during a race. The accepted belief is that the divergence in performances is not due to the effort exerted – but to differences in maximal capacity. Theoretically, if both elite and slow runners work at 90 per cent of maximum during a 10-K race, but the elites have much higher capacities, then it’s inevitable that they’ll be faster. At least, that’s what runners usually say.

Of course, many elite athletes don’t really believe that, thinking instead that they have higher abilities and greater tolerances of hard work, compared to slower runners. And the also-rans usually don’t quite believe that they’re putting forth as much effort as the top people, even when they reach the near-collapse point at the end of a 10K, while the elites are looking fresh as daisies during their cool-down jogs.

What’s the truth? To find out, researchers at the University of Cape Town Medical School recently studied eight fast and eight average runners. The fast individuals averaged 33 minutes for the 10K and 74 minutes for the half-marathon, while the average harriers clocked about 40 minutes for the 10K and 94 minutes in the half-marathon.

The fast and average runners were about 30 years old and 5’11’ in height, but the fast runners had less total muscle mass, were lighter (151 vs. 170 pounds), possessed a higher average VO2max (61 vs 56 ml/kg.min), had higher max heart rates (198 vs. 187 beats per minute), and tended to be leaner (13 vs. 17 percent body fat).

To determine actual effort during competition, at least from a cardiovascular standpoint, each runner wore a heart monitor during both a 10-K and half-marathon race, conducted under moderate environmental conditions (between 46 and 56 degrees Fahrenheit). Each individual pressed a button on the heart-rate monitor receiver after every kilometre, allowing average speed, heart rate, and percent max heart rate to be determined for each kilometre.

The results supported the popular belief that fast and average runners exert roughly equal efforts during competitions. Basically, the fast (33-minute) runners averaged 90 per cent of max heart rate during the 10K, while the average athletes checked in at a very similar 89 per cent of max. In the half-marathon, the results were about the same – 91 per cent of max for the fast harriers and 89 per cent for the slower runners.

The message? It’s not necessarily effort which pushes the fast runners along more quickly than the slower competitors in 10-K and half-marathon races, since both are working at about 90 per cent of maximal cardiovascular capacity. The difference is that the faster people have higher capacities (greater VO2maxs, loftier max heart rates), less fat to lug around, and greater fatigue-resistance in their leg muscles.

This equivalency of cardiovascular effort ends up creating a somewhat bizarre scenario on race days. As Nick Troop, 4:20 marathoner and publisher of Runner’s World in the UK likes to say, ‘When I run the marathon, I work as hard as the elite athlete does – but for twice as long, even though I’m only about half the athlete that he is’. Life just isn’t fair!

Aroused hearts

The Cape Town research raised another interesting point: heart rates during competition are usually higher than those achieved in training, even at comparable running speeds. For example, when running at half-marathon velocity during a workout, the runners averaged just 82 to 84 per cent of max heart rate, yet during an actual half-marathon race they were at 89 to 91 per cent of max.

The researchers attributed this to ‘nervous-system arousal’ (being ‘psyched up’) during the actual race, which probably spiked heart rates to higher-than-usual levels. If heart rate at a particular pace during a race is usually higher than heart rate at the same velocity during practice, then it means that:

  1. If you run at your goal race pace during practice while determining the heart rate associated with that pace with a heart monitor – and then decide to run at that heart rate during your race (to avoid having to worry about exact pace between mile or kilometre markers and to make sure you’re not exceeding your own cardiovascular capacity), you will usually underperform during the race. That’s because the arousal created by the race will bring your heart up to its goal rate of beating at a slower running speed than you could actually sustain during the competition.
  2. If you decide to run a race at a fixed percentage of your max heart rate, there could also be trouble. For example, let’s say that you know your max heart rate and you decide to run a marathon at 84 per cent of max. Trouble is, the tension and nervous-system arousal created by being in the race may scoot your heart up to 84 per cent of max at a slower running speed than you could actually maintain in the race.

That’s why it makes sense to do your training and racing at prescribed running paces, rather than heart rates. That 6:25 per mile goal pace that you practise so diligently in training – under a variety of different conditions – will bring you to the finish line in your hoped-for time in a real race. Meanwhile, that 90-per-cent-of-max heart rate you’ve practised and prepared for and insist on staying with in the race might be reached too easily in a competitive situation, because of your heightened psychological state (or because of environmental factors), bringing you home in a slower time than you could actually achieve.

To put it another way, you might practise running at 6:25 per mile during training, a level of effort which consistently causes your heart to settle in at 90 per cent of max. In a race, that same pace might shoot your cardiac centre up to 93-94 per cent of max, but the pace won’t feel any more difficult than it did during training. You can keep it up, despite the higher heart rate. Meanwhile, if you were glued to 90 per cent of max heart rate, you’d run the race more slowly than you actually could.

Owen Anderson

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