Is there anything to the theory that overly cushioned shoes make you MORE prone to stress fracture?

Get some racing flats and you will see.

A guy called Steve Robbins who's at McGill Univeristy has studied this for a long time. His research found that more cushioning increases the impact of each stride but lessens the sensation of impact. I just saw a similar article from a guy at Northumbria University whose research says the same thing. If I can recall the name I'll come back and post it.

The reasoning goes that cushioning reduces injury-risk in the near-term by reducing stress on the bones but in the long term this reduced stress leads to weaker bones, tendons and muscles in the foot and lower leg. This weakness makes you susceptible to certain injuries like stress fractures. Most serious runners run mileage in cushioned trainers and their workouts in flats or spikes are enough to keep their feet strong.

It's likely the increased flexion that weakens the bone rather than the impact

Mick Wilkinson is the other name to check.

Today I did some mile reps on the road with some racing flats. One thing I love about running in them is how I feel the ground more and feel more smooth. I'm going to slowly transition to doing all my runs in flats.

3hr-marathoner wrote:

The reasoning goes that cushioning reduces injury-risk in the near-term by reducing stress on the bones but in the long term this reduced stress leads to weaker bones, tendons and muscles in the foot and lower leg. This weakness makes you susceptible to certain injuries like stress fractures. Most serious runners run mileage in cushioned trainers and their workouts in flats or spikes are enough to keep their feet strong.

No, force has to go somewhere, it doesn't just disappear because you are wearing thicker shoes. The force that pushes back into you is the product of how fast you are running. Don't confuse force with pressure.

Bump for more comments.

I ordered some Bostons, so we'll see how this experiment with firmer shoes goes.

In 45 years I have had a variety of soft-tissue injuries, but no bone issues. I have always trained in a rotation of shoes with various degrees of cushioning. About 30% of my miles are in minimalist flats or barefoot. About 20% are in Hoka-type cushioned shoes.

I almost never run in the same shoe two days in a row, much like my runs constantly vary. In my 60s I am injury-free completely, though rather slower than I would like to be.

Thanks. I pulled up a publication by Dr. Robbins from 1987. Here's a quote from the abstract:

He is a barefoot evangelist, as you can tell from his personal website if you google him (he calls shoes "dysfunctional body art"). So, as someone who likes a layer of rubber between my foot and the road, that doesn't really help me much. But it's interesting, I guess.

From everything I have seen and heard, it comes back to our favorite answer to everything: "It depends." Ugh.

What it appears to depend on is what kind of runner you are. In some (perhaps most) cases, a more cushioned shoe can actually lead to higher total impact forces. This happens because a cushioned shoe will dull the sensation on the bottom of our feet, where we're designed to register those forces. In the short run, the SENSATION of the impact is being distributed up the chain, but in the long run, you might be putting more force on your knee, hip, etc than is necessary, which then leads to an injury somewhere.

BUT... If you're not careful, running with less cushion could lead to stress fractures in the foot. That's why it's supposed to take several months to transition to minimal shoes. If you've spent a lifetime in built-up shoes, jumping into less cushion is a recipe for disaster.

All this is theory, of course, as there are now studies to back just about anything up. MY theory, just from running around in different shoes and going from a beginner who thought running was simple to the kinetic scientist/physiologist/dietician I am today (kidding, but it feels that way), I would say the highly cushioned shoes are a problem for weaker runners, for the reasons above. Stronger runners (as in stronger hips, butts, hammys, quads, core, heart, stride) are less at risk for problems with cushioned shoes (and less at risk for everything, when you think about it), so if they just want to be more comfortable, they have the backside to handle it.

A long time ago I read this advice: Go for the least amount of shoe you can manage. But most people underestimate what they need, and overestimate their ability to 'manage'.

meta-metatarsal wrote:

He is a barefoot evangelist, as you can tell from his personal website if you google him (he calls shoes "dysfunctional body art"). So, as someone who likes a layer of rubber between my foot and the road, that doesn't really help me much. But it's interesting, I guess.

That's the secret. A layer of rubber, not a layer of foam.