Usain Bolt doesn’t worry about his running economy. He powers off his forefeet to generate as much speed as possible for just 10 to 20 seconds, then he gets to stop and recover. Oxygen use doesn’t concern him.
On the other hand, marathoners strive for a high economy – that is, low oxygen consumption – because their event lasts for three to five hours, or more. Studies have shown that 80 to 90 per cent of midpack marathoners land on their heels. Presumably the body naturally chooses heel-landings to ensure good running economy.
But what about guys who are fast in a half-marathon, but not gold-medal fast? Are they more economical with a heel landing or a forefoot/midfoot landing? A new study from the University of Spain, the first of its kind, set out to find the answer.
The researchers ran a group of 20 runners through several treadmill tests. Half the group were rearfoot strikers, and half midfoot/forefoot strikers (It has become common to lump these two together). All were allowed to use their normal training shoes, as long as the weight of each shoe fell between 250 and 300 grams.
All subjects had completed a half-marathon within six weeks of the testing, with the rearfoot strikers averaging 1:10:59 and the midfoot strikers 1:10:21. Both groups had been running for an average of 12 years, and covered about 88km per week in training. They also had the same body builds, equal VO2 max scores, and nearly identical stride lengths and stride rates.
In other words, the two groups appeared to be very similar on a number of key running variables.
But the rearfoot runners were significantly more economical at 5:29 per kilometre and 4:38 per kilometre, and somewhat more economical at 4:01 per kilometre.
Why? The researchers note that the rearfoot runners “showed longer contact time (between 7% and 13%) and shorter flight time (between 13% and 35%.). The observed differences in these biomechanical parameters could explain the differences in running economy.”
So if you’re among the majority of runners who land first on your heels, there’s no reason to think that a different footstrike will improve your running economy. “Based on our study, I wouldn’t recommend a footstrike change to typical rearfoot strikers who run the half-marathon at slower than 3:45 per kilometre,” lead author Ana Ogueta-Alday told Runner’s World.
However, if you’re training to beat Usain Bolt… well, good luck with that.
