Does Rotating Your Shoes Reduce Your Risk of Running Injuries?

More than a few people are guilty of training in the same ratty old pair of running shoes for months, logging hundreds or possibly, even thousands of miles on them before finally heading over to the local running shoe store to get a replacement.

In the back of your head, you probably know that you should replace your running shoes after about 400 miles, as their cushioning properties change.

Although running in old shoes hasn’t been directly connected to injury, there is evidence that your body changes how your muscles are activated when you run in worn-out shoes, which could plausibly increase your risk of injury.

So old shoes aren’t the greatest for your feet; that’s old news.

But some runners take paying attention to the condition of your footwear to a whole new level by using two pairs of shoes for their running.  Not at the same time, of course—they practice shoe rotation, wearing, say, their Nike shoes on one day and their Sauconys the next.

The most often-cited reason for practicing shoe rotation is to give time for the shoe’s foam to recover from a run.

Allowing your shoe a day to “rest” lets the foam cells that make up the midsole of your shoe decompress, enabling the shoe to last longer, or so the theory went.

But, does this theory hold true? If not, what other reasons could there be to rotate your shoes?

Will EVA foam decompress more if allowed to “rest” by rotating shoes?

Unfortunately for shoe-rotation enthusiasts, that idea was debunked by a 1985 study that examined how the cushioning properties of a shoe declined as the shoe accumulated more mileage regardless of “rest” time between runs.

Stephen Cook, Marcus Kester, and Michael Brunet at Tulane University showed that even after a 24 or 48-hour “rest period,” the cushioning of a shoe showed no evidence of recovery following a simulated run on a mechanical impact-testing machine.

A shoe’s cushioning properties do decline significantly after several hundred miles of running on the roads, but there’s not much you can do about it.

Unlike your body, which does a remarkable job of repairing itself after a day or two of rest, the EVA foam in your shoes can’t recover.

This is not to say that shoe rotation fell out of favor.

Plenty of runners still found that their legs felt better and they avoided injury by switching up their shoes every other day.

The support for shoe rotation remained anecdotal until the publication of a study last year by a group of researchers in Luxembourg.

Malisoux et al. followed 264 recreational runners over a five-month period and evaluated which ones suffered running injuries.  Predictably, they demonstrated that having a history of running injuries predisposed you to getting another one.

But more interestingly, they found that runners who practiced “parallel use of different running shoes” (i.e. shoe rotation) incurred injuries at only 61% of the rate of injury of the group as a whole.

If it’s not cushioning, how could shoe rotation prevent injury?

Given that shoe cushioning recovery can’t explain this finding, how else might shoe rotation protect against injury?

One of the other findings of the study offers a clue: participating in sports other than running was also protective of injury.

This finding isn’t new—elite runners who played ball sports like soccer or basketball suffer fewer stress fractures than those who did not (here’s the research)—but it indicates that changing up the stresses on your body may be beneficial when it comes to preventing injury.

The actual magnitude of forces in your body when you’re out for a run isn’t very big compared to, say, leaping into the air to catch a frisbee or making a sharp cut across the court to hit a tennis ball.

The problem is that the forces involved with running are extremely repetitive—an hour-long run will likely rack up over ten thousand foot strikes, with each impact very much like the previous one.

• By changing up the forces on your body even slightly by wearing a different pair of shoes, you might give a stressed part of your feet or legs a chance to rest up a bit.

• This effect could also be from stressing and strengthening, in smaller doses, the muscles in your feet and lower legs. This is especially true if you rotate between two different models of shoe.

Now, this study was far from perfect.  It wasn’t a randomized controlled trial, the gold standard of testing a measure of preventative medicine.  The runners who practiced shoe rotation may well have been more conscious about avoiding injury in the first place, which spurred them to try rotating shoes.

Conclusion

With a trial like this, it’s hard to separate cause and effect.

One of the other findings of this study was that runners who ran further in their individual runs got injured less than those who ran shorter: does running far prevent injury, or were injury-prone runners just less likely to run far?

This study has almost surely inspired other researchers to undertake larger and more rigorous studies to test the idea of shoe rotation further, as it could be an extremely cheap way to prevent injuries.

Though the initial cost is higher, two pairs of shoes should last you just as long in parallel as two pairs worn sequentially.

Until more research comes in, we can’t be 100% sure that rotating between two or more different pairs of shoes will prevent injury, but as long as both pairs feel comfortable to wear and to run in, it’s very unlikely that you’ll do yourself any harm.