Thursday, April 21, 2016

Your Running Style Definitely Changes When You're Tired

Picture by richseow from Flickr
"I'm a fore/ mid foot runner, I don't land on my heels etc". I often get responses like this from my patients who are runners when I ask them if they have changed their running style recently.

To which I will reply, "How about when you're tired?"

I remember when I was still racing triathlons the official race photographer will email pictures of the race and I'll be quite amazed by the transformation. Often the smooth stride at the start of the run is often reduced to a not so pretty shuffle near the end of the race - (exception is when I'm sprinting or trying to out sprint another competitor at the end).

Is that the same for you as well? Well, I looked through pictures of my school boy track races I used to run, my stride looked pretty good all the way, but that's for track races (which are much shorter) and many moons ago (I was much younger then).

Most research so far has focused on fresh (and not fatigued) runners usually on a treadmill. Not much use then when your running style tend to fall to pieces when you get tired.

Well, I'm not the only person wondering if you running stride changes when you're tired. A small group of 14 habitual forefoot runners who typically ran about 30 miles (48 km) a week were studied. They ran to exhaustion (average of 15 minutes) while researchers took detailed measurements of their stride at both the start and end of the run.

There were significant changes even after only 15 minutes. Eight out of the 14 runners studied were landing farther back toward their heels by the end of the run. The ankles and knees were more flexed during the gait cycle suggesting that this may give a little more shock absorption when the ankle and calf muscles get too tired to provide sufficient shock absorption.

This shows that our running stride gradually changes as we fatigue, regardless of whether you start off heel striking, mid foot or forefoot striking.

Hence the authors suggest this can be a problem running in minimalist/ barefoot inspired type running shoes as your muscles fatigue during a long race and your land on your heels without sufficient cushioning. I've previously written that will reduce overall impact forces

You can of course gradually increase your mileage in your minimalist/ barefoot inspired type running shoes to increase your strength and build up fatigue resistance as I've previously written that your own muscles and tendons and a good running technique will reduce overall impact forces.


Reference

Jewell C, Boyer KA and Hamil J (2016). Do Footfall Patterns In Forefoot Runners Change Over An Exhaustive Run? J Sports Sciences. 22: 1-7. DOI: 10.1080/02640414.2016.1156726.

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