RoadID

Subscribe via email

Enter your email address below to receive the latest tips for beginning runners:

Delivered by FeedBurner

Interesting Study about Usain Bolt that Every Runner Should Know


Lately, I've been wondering how Usain Bolt would fare on a run from Paris to Beijing. And thinking about how Bolt is like an ultrarunner. The topic also adds information to the recently much-discussed question of stride rates, and their meaning.

I began thinking about Bolt and Paris-Beijing because I was reading a two-year-old article from the European Journal of Physiology about a guy, Philippe Fuchs, who actually did run from Paris to Beijing. He covered about 5,100 miles in 161 days for a daily average of 32 miles per day. Since Fuchs was tested by a group of physiologists before and after his run, we now know how it affected him, in at least several interesting ways.

First, how is Bolt like an ultrarunner? Easy. Neither cares much about running economy. Bolt consumes oxygen like a fireball. He doesn't even have to breathe during a 100. If he goes deep into oxygen debt, it's no big problem, because he's going to stop in a second or two.

Strangely enough, running economy doesn't matter to ultrarunners either, at least not the Paris to Beijing types. They're mostly concerned by their body's ability to keep absorbing muscular and skeletal punishment day after week after month. After all, Fuchs wasn't even in a race–he wasn't trying to go "fast." He was merely trying to get to Beijing on some sort of self-imposed schedule.

You would think that 161 days of a marathon-plus per day would turn you into a lean, mean running machine. But that doesn't happen, at least not when it comes to running economy. Not even when there are numerous changes in the direction that you might think would improve economy.

For example, Fuchs lost five pounds during the run, and his percent body fat dropped from 21.5% to 16.5%. You'd think this would make him more oxygen efficient. It didn't.

His stride became shorter and "smoother," the word used by the physiologists to describe his decrease in aerial time with each stride.You'd think this would make him more oxygen efficient. It didn't.

Why not? Because running economy isn't crucial to an ultrarunner. You don't require a super cardiovascular system to pad along at 10 to 12 minutes per mile. You need a body that just won't break down. You need to improve your mechanical efficiency, but not necessarily your oxygen efficiency.

That's exactly what Fuchs did on the road to Beijing. (I imagine it was mostly subconscious; after a couple of successive 32-mile days, his body went into preservation mode, and took over.) He reduced his landing force (see table below) and also his loading rate (not shown). But his oxygen efficiency, or running economy, decreased by six percent.

This illustrates one of the conundrums faced by those attempting to run with shorter strides. It may in fact reduce your injury rates. It won't necessarily make you faster. (I'd say this is a pretty good trade-off for someone who's injured or coming back from injury.)


Runner Philippe Fuchs       Stride rate at 10:00/mile       Air time in seconds     Vertical landing force
                                                                                                                             (body wts)
Pre Paris-Beijing                        180                                         .5                            2.7

Post Paris Beijing                      192                                        .35                            2.4



Could Usain Bolt Run from Paris to Beijing?

--


I think most runners really look at Usain Bolt not only because he's the fastest man on earth. Usain Bolt has a very efficient run and I have never heard him get injured. Well, do you really think he canrun from Paris to Beijing? Let me know.


No comments:

Post a Comment