DR. LIEBERMAN: I think there's a number of key elements to good running form. The first

is not to overstride. Overstriding is when you stick your leg out in front of you and

you land with your foot in front of your knee and really way in front of your hip. A lot

of people think they're running hard when they do that. You know why? Because they are

running hard. Because when you stick your leg out in front of you, you actually decelerate

in the time it takes the center of mass of your body to get over your foot, you're actually

losing energy. The other thing that happens when you overstride is that you stick foot

out in front of you and make your leg stiffer. And you have what's called an impact peak

and you have this shock wave that ripples up your body. But when you land without an

overstride you don't have that jolt of force and you're much less likely to get injured.

It's just a better way to run.

Another key element to running is to land with a pretty flat foot. I think that most

good runners tend to land on the ball of their foot. It just happens naturally. If you don't

stick your leg out in front of you, you will not land hard on your heel. You'll land on

the ball of your fit or your mid foot stride, but it's a gentle landing.

Don't lean. A lot of runners lean forward at the hips. That's another total evil. Be

vertical from the hips up.

If you can hear your feet, if your feet are landing really hard. If you're thumping as

we call it in our lab, it's a sign that you're running poorly. The thump is the sound of

the collision of your body hitting the ground. Running should be light and gentle and collision

free so if you're making a lot of noise, you're running poorly.

And then finally, the most important thing if you're learning to run properly and you

haven't been doing this for a long time, listen to pain. Don't overdo it. Transition really

slowly and gradually. Your body is not designed for this explicitly. If you transition into

learning how to run properly too fast, you are guaranteed to injure yourself. You have

to adapt your body. Everybody can learn to run this way, or most people can learn to

run this way, but you can't do it overnight.

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