I'm a heel striker. Should I try to change?

In the Nature article by Lieberman, he and the other authors specifically stated at the end that though they found the forefoot strikers and un shod runners landed with less impact force, this did not necessarily translate to reduced injury rates.

I would echo a common theme here; if you've not had injury issues being a heel striker, you're likely to be OK. One could argue in your efforts to change, you may develop ankle, AT and calf problems. There are a lot of people out there who've tried to do the barefoot thing or Five Fingers thing (because it's supposedly the right way to run), developed injuries, and haven't wanted to admit it.

There is probably a reason why the heel is so durable and has so much soft tissue around it. It's the least sensitive area on our body. Probably by design.

Realize this; if we all ran as fast as the elites did, even for 200 meters, we'd probably run on the front part of our foot, but we'd pay for that. Even many of the elite don't necessarily run/race on their forefoot.

Some things to consider; run more in racing flats or very light weight trainers. They have less of a heel lift, so your foot will naturally land a bit more flatter or on the mid-foot. You can also work on cadence, so you're getting more foot strikes, if you'd like..............but if it ain't broke, I wouldn't go trying to change a bunch of things. Good luck.

777 wrote:

J.O. wrote:

Except that nobody actually runs like that.....

So many biomechanics experts here repeating the same old nonsense.

I have personally witnessed several runners who run exactly like that. I counted their stride frequencies myself! I've even seen a few guys under 160 strides per minute, and this is at 7-minute miles or so! You really have to see it to believe it. Most "hobby joggers" have very low stride frequencies. Next time you're at the track, count the number of times a jogger's right leg hits the ground in 30 seconds. You'll probably count 42 or so--that'd be 168 strides per minute. It's no surprise that the 160ish strides per minute runners had lots of injury problems, and terrible footspeed.

Why is there a co-relation between 160ish strides per min and injury?

We have a guy in our community who is big on the forefoot running thing. He talks less about injury rate, and more about stored energy in the achilles?

I have always told people the more relaxed your body is the faster you run. If you are worrying about your footstrike, you tense up which could lead to slower times.

777 wrote:

J.O. wrote:

Except that nobody actually runs like that.....

So many biomechanics experts here repeating the same old nonsense.

I have personally witnessed several runners who run exactly like that. I counted their stride frequencies myself! I've even seen a few guys under 160 strides per minute, and this is at 7-minute miles or so! You really have to see it to believe it. Most "hobby joggers" have very low stride frequencies. Next time you're at the track, count the number of times a jogger's right leg hits the ground in 30 seconds. You'll probably count 42 or so--that'd be 168 strides per minute. It's no surprise that the 160ish strides per minute runners had lots of injury problems, and terrible footspeed.

You are completey clueless about biomechanics.

J.O. wrote:

You are completey clueless about biomechanics.

Well please, enlighten me.

40s jogger wrote:

Why is there a co-relation between 160ish strides per min and injury?

Because of the way your muscles and nerves work, your body has a limited window of "acceptable" stride frequencies. 200+ is too high for anything less than an all-out sprint, because to move your legs that fast, you need to involve all of your fast-twitch muscle fibers, which are the only ones capable of firing that quickly. Lower than about 150 doesn't work either, because then your ground contact time is too long to use the stretch-shortening cycle, which is a muscular mechanism that allows you to store energy on impact and release it when you push off--just like a spring or a pogo stick.

So assuming that you are limited to operating within this window of stride frequencies, if you are going from point A to point B (say, 10 miles at 7 minute pace), there is a certain amount of work to be done to move your body those ten miles. If you can spread that work out over more steps, that means less work (and less impact) per step, so less mechanical stress on your body. Additionally, when you run with a low stride frequency, you tend to be "boundy"--spending a lot of energy going UP instead of FORWARD. Now, these arguments involve a bit of hand-waving, but are experimentally verified, for example:

which shows that increasing stride rate reduces the impact forces in the joints. Unfortunately, since this study is so new, I have not actually seen the full version yet, but there are similar studies that find reductions in impact forces at higher stride frequencies. Jack Daniels' study at the '84 Olympics comes to mind--this is where the "magic" 180 strides per minute comes from. That was the lowest stride frequency he found out of any of the elite athletes. I think there are some old posts here on letsrun by Jack Daniels (posting as "jtupper") talking about stride frequency. I'm sure he can explain it much better than I can.

Thank you 777

777, would you advise consciously working on increasing my stride frequency, or training in lighter shoes to build up to that?

Seems like getting the stride frequency up should be first priority. Otherwise you'll just be doing unnecessary pounding in the lighter shoes. There is something to be said about cushioning "allowing" a lower stride frequency--try running on a track, barefoot, and I bet your stride frequency will go up. Of course, it's not practical to do all of your mileage like that! Be aware that it might take a while (weeks to months) to get up to 180 if you are down in the 160s. It'll feel very weird at first.

Here's some threads where Jack Daniels (jtupper) has posted regarding the topic:

http://www.letsrun.com/forum/flat_read.php?thread=859810&page=1

http://www.letsrun.com/forum/flat_read.php?thread=149099&page=0

http://www.letsrun.com/forum/flat_read.php?thread=1582939&page=1

http://www.letsrun.com/forum/flat_read.php?thread=2165896&page=2

No, you don't aim for a higher stride rate to get more speed. You push off harder, and stride rate comes naturally.

Do you really think that slow runners are slow because they are only doing 160 strides per minute?

I hope you don't believe that? it would be very stupid indeed.

J.0. wrote:

No, you don't aim for a higher stride rate to get more speed. You push off harder, and stride rate comes naturally.

Do you really think that slow runners are slow because they are only doing 160 strides per minute?

I hope you don't believe that? it would be very stupid indeed.

Actually it depends on the individual. Some runners accelerate to top-end speed by increasing stride rate, and some increase stride length. Some do both. See:

and also

Enomoto et al. (2008). Biomechanical analysis of the medalists in the 10,000 metres at the 2007 World Championships in Athletics, New Studies in Athletics

Steve Magness wrote a very good piece on the issue discussing these two studies:

Low stride frequency is not always indicative of being a slow runner. I said it limits speed, and by that I mean it can sometimes limit top-end sprinting speed depending on how your form changes (if it does at all) as you accelerate. Slow runners TEND to have low stride frequencies, and this might simply be because they don't spend very much time (if any) running FAST, which demands a quick stride frequency. However, I've known a few very good runners who have impeccable form at high speeds, but as they slow to an easy pace, they decrease their stride frequency, and end up having the "boundy" stride I talked about earlier, wasting a lot of energy going up and down. if their form improves at high speeds this won't preclude race performance, but will cause them to be more susceptible to injuries.

The boundy style you refer to is not a wrong way to run, but somewhat inneficient because the vertical displacement limits stride length.

Young or inexperienced runners with slow stride rates should NOT be encourage to increase stride rate, but to learn to lengthen stride length. As they do this and become more efficient they will get faster and that is where the stride rate comes from, because the faster you go, the shorter the ground contact time and thus the faster the stride rate.

But telling runners to run with 180 strides per minute is just plain wrong and shows a lack of understanding of the basics of biomechanics.

Looking through those old threads you linked to, it is easy to see how people have bought into the mythology, including Jack Daniels. His anayses have overlooked the natural development of longer stride lenghts and only measured the economy.

What I mean is that to develop a long stride the way that young runners do, it is inevitable that a developing runner will not be as economical with a 2 meter stride if they are only doing 10 miles per week, but as they build endurance, they will soon become very fast over long distances.

160 x 2 meter strides per minute = 320 m/minute, that's 5.01/mile

When they get up to 180, that's 4.28 per mile. That's why them Kenyan and Ethiopian kids be so quick, they have more powerful strides.