Solve the Over-Stride
Fix one thing in your running form - land with your shin vertical - and the rest of your mechanics follow.
- Difficulty
- Moderate
- Time to result
- ~months to results
- Steps
- 5
- Confidence
- 90%
Lieberman argues that most knee pain in runners comes from how people run rather than from running itself, and that the single highest-leverage correction is eliminating the over-stride. Over-striding means throwing the leg out well in front of the body and landing on a stiff leg, which produces a large braking force and a hard heel collision. His lab's barefoot-running work, published on the cover of Nature, showed that unshod runners more often land on the ball or middle of the foot and then let the heel down, avoiding the impact peak that cushioned heels make possible. Rather than asking runners to consciously change their footstrike, Lieberman's instruction is to fix the over-stride and let footstrike, cadence and loading sort themselves out.
Origin
Lieberman's lab began studying barefoot running a few decades ago on the reasoning that humans have run for millions of years and were barefoot for almost all of it, so the question of how people ran before shoes was answerable biomechanically. That work produced the Nature cover paper on impact peak collisional force.
Core principles
- 01What matters is how you run, not what is on your feet.
- 02A stiff leg landing far in front of the body means more force and more braking.
- 03Land with the tibia vertical and the ankle beneath the knee, and the rest works out.
- 04Every coach on the planet agrees over-striding is bad - it is the least controversial fix available.
- 05Nothing comes free: form changes shift load rather than removing it.
- 06Form changes must be introduced gradually, because the tissues taking the new load need time to adapt.
How to run it
- 1
Stop trying to fix your footstrike
Do not consciously chase a forefoot landing. Lieberman's explicit instruction is not to worry about how you are going to hit the ground, because footstrike is downstream of stride length.
Watch out Deliberately forefoot-striking while still over-striding adds calf and Achilles load without removing the braking force - the worst of both.
- 2
Raise your cadence into the 170-180 range
Target roughly 90 strides per minute, or about 180 steps per minute; 170 to 180 steps a minute is about right. Higher turnover naturally shortens the stride.
Pro tip Cadence is the easiest variable to measure objectively - most watches report it, and a metronome or a playlist at tempo will entrain it.
- 3
Shorten the stride so the shin lands vertical
Aim to land with the shank - the tibia - vertical, so the ankle is directly below the knee rather than out in front of it. This is the single check that defines whether you are over-striding.
Pro tip Have someone film you from the side at normal pace; the vertical-shin test is obvious on a freeze frame and needs no lab equipment.
- 4
Avoid the ballerina overcorrection
Do not run high up on your toes. Lieberman flags this as a common failure mode among people trying to change form, and it is punishing on the ankles and calves.
Pro tip If you land forefoot, let the heel come down afterwards - that is what barefoot runners actually do.
Watch out Running permanently on the toes loads the Achilles continuously with no relief phase.
- 5
Transition gradually and build the supporting strength
Introduce the new mechanics over weeks, not sessions, and build calf, Achilles and foot strength alongside. The load has moved, not vanished.
Watch out People who switch from heel striking to forefoot striking abruptly commonly develop Achilles tendon problems, calf problems, and foot problems if their foot muscles are not strong enough.
In the wild
Lieberman's group worked out the biomechanics of barefoot versus shod running and published it on the cover of Nature. Modern cushioned heels let a runner effectively run the way they walk - landing on the heel. Barefoot runners more often than not land on the ball of the foot and then lower the heel, a forefoot or midfoot strike that prevents the foot crashing into the ground and generating an impact peak collisional force.
→ The mechanism explained why barefoot-style running produces a lighter, gentler landing and less force around the knee, where runners are injured most.
Lieberman offered Bartlett a live thought experiment: take your shoes off and run up Lexington Avenue outside the studio. He guaranteed that within a few steps Bartlett would stop landing on his heels and start landing on the ball of his foot - not through instruction, but because heel-striking barefoot on pavement simply hurts.
→ It demonstrates that the protective form is the body's default once the cushioning that masks the collision is removed.
Common mistakes
Believing the shoe determines the form
Lieberman is direct that what matters is how you run, not what is on your feet. Buying minimal shoes while keeping an over-striding gait changes the cushioning without changing the mechanics that cause the load.
Switching form abruptly
The trade-off is real: forefoot striking transfers work to the calves and Achilles, which must let the heel down. Doing it overnight produces Achilles tendon and calf injuries in place of the knee problem you were solving.
Running like a ballerina on the toes
Overcorrecting into a permanently high, toe-only landing is, in Lieberman's words, really hard on your ankles and your calves, and is a common outcome when people chase footstrike rather than stride length.
Is it for you?
Best for
Recreational and distance runners with recurring knee pain, and anyone considering a move to barefoot-style or minimal-shoe running.
Not ideal for
Runners with existing arthritis, for whom Lieberman notes running is excruciating regardless of form, and anyone with an acute Achilles or calf injury who should not be adding load to those tissues.
From the transcript
“a barefoot style tends to be a high stride rate or high stride frequency. So 90 strides per minute or 180 steps per minute roughly.”
“Over striding is when you throw your leg out way in front of you when you land and that leg is a stiff leg. So…”
“a good runner lands uh with their with their shank with their tibia vertical. So their ankle is below their knee.”
“don't worry about how you're going to hit the ground. Just worry about your over stride. If you solve your over stride you're more likely…”
“you can't just suddenly become a barefoot runner and start forefoot striking. If you're going to switch you have to switch gradually and slowly and…”
From the episode
Harvard Professor: "10,000 Steps A Day" Is A LIE! Revealing The 7 BIG LIES About Exercise, Sleep, Running, Cancer & Sugar!!! Daniel Lieberman
Harvard Professor