Super cushioned running shoes are all the rage, but aren’t foolproof

Super cushioned running shoes are all the rage, but aren’t foolproof

Runners wearing maximalist running shoes pound harder and pronate more than in standard shoes.

running in sports shoes
(Photo: Unsplash/Bruno Nascimento)

Anyone who runs or spectates at races has probably noticed that stacked, generously cushioned running shoes have become almost ubiquitous. But running in those thickly cushioned shoes could affect a runner’s form in sometimes surprising ways, according to a series of new studies of maximalist running shoes and recreational athletes.

The studies, among the first to examine the biomechanics of ordinary runners wearing super-cushy shoes, find that some of them pound harder and pronate more than in standard shoes. The results have implications for runners’ comfort, injury risks and perhaps for our thinking about whether the increasingly popular fat-soled models are right for us.

Thickly cushioned running shoes have largely supplanted the minimalist, barefoot-style shoes that many of us wore a few years ago. Those light, barely cushioned models were expected to nudge us into running in a more natural way, reducing the risk of injuries.

running in a park
(Photo: Unsplash/Arek Adeoye)

But some runners did get hurt in minimalist shoes, and others did not enjoy the shoes’ skimpy feel. And so, as often happens, interest swung recently toward the other extreme, of running shoes with plenty of cush.

Those light, barely cushioned models were expected to nudge us into running in a more natural way, reducing the risk of injuries.

These maximalist shoes, which generally feature high, foam-filled midsoles (and sometimes other high-tech additions, such as carbon-fiber blades), are reputed to be more comfortable, less likely to contribute to injuries and, in the case of some models, like the popular Nike Vaporfly, faster than less-cushioned shoes, making them especially popular with competitive athletes.

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But few studies have examined the effects of maximalist shoes on how average, recreational athletes run. So, for the new studies, a group of researchers at Oregon State University-Cascades in Bend, Oregon, began a series of experiments.

The first of these, which was published in 2018 in The Orthopaedic Journal of Sports Medicine, involved 15 female runners. The researchers supplied these volunteers with neutral running shoes, which contain an average amount of midsole cushioning, and maximalist, thickly cushioned shoes.

The women donned each type of shoes in turn and ran over force plates embedded in a long track, while the researchers filmed them using motion-capture technology. Immediately afterward, the women ran 5 kilometers on a treadmill and then raced along the track again.

 runners at a Competition
(Photo: Unsplash/Nicolas Hoizey)

Comparing their form, the researchers noted that the women almost uniformly landed harder in the maximalist shoes than the neutral pair and pronated more – meaning that their ankles rolled inward slightly – when they pushed off.

Those changes in running form could be expected to increase the risk of running injuries, if they lingered. But that study looked at only one run in each type of shoe. So, for a follow-up study, which was published last year in the American Journal of Sports Medicine, the researchers had runners again stride over force plates in neutral and fat shoes, but then also wear the maximalist pair for six weeks of training, before they repeated the testing. As before, the runners tended to impact the ground with greater force and pronate more in the maximal shoes during their first visit to the lab. But those changes in running style did not lessen during the six weeks. In effect, the runners did not adjust to the shoes. They continued to thwack the ground and roll at the ankles a bit more in the stacked-sole shoes than the neutral ones.

Finally, for the most recent, related experiment, which was published in January in the Journal of Science and Medicine in Sport, several of the researchers asked a shoe company (New Balance) to custom-alter a pair of their neutral shoes, removing or adding foam, so that the same model could serve as a minimal, neutral and maximal shoe. These customized shoes would allow the scientists to focus exclusively on the role of cushioning in the runners’ form.

Man in running shoes
(Photo: Unsplash/Adi Goldstein)

The researchers then rounded up a new group of 20 male and female recreational runners, gave them the custom shoes and repeated the force-plate measurements and motion capture. This time, few of the runners thudded as forcefully in the maximalist shoes, but they continued to pronate more than in the other models.

Taken as a whole, the three experiments suggest that extra cushioning does influence several aspects of how we run, says JJ Hannigan, now an assistant professor of kinesiology at San Jose State University, who, with his postdoctoral adviser, Christine Pollard, and others at Oregon State, was an author of each of the studies.

Extra layers of foam could blunt road feel, which is our bodies’ sense of where the ground is.

In particular, the stacked soles of the maximalist shoes seem to subtly affect balance.

“If you extend a shoe’s height, it will tend to be more unstable,” Hannigan says, which is likely to increase ankle movement and pronation.

Likewise, he says, extra layers of foam could blunt road feel, which is our bodies’ sense of where the ground is. In that case, our muscles, brains and nervous systems might be less able to precisely coordinate and anticipate footfalls as we clop against the earth.

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None of the three studies tracked actual injuries among the runners wearing the maximal or other shoes, though, so the authors cannot say if extra padding contributes to or reduces the chance of getting hurt. They also were not looking at running speed or how runners felt about the fat shoes, which are factors that can matter when choosing a shoe. Hannigan hopes to look into some of those issues in future studies.

For now, if you are interested in maximal shoes, “visit a running store and try them out before buying,” Hannigan says, and ease into training with them slowly.

By Gretchen Reynolds © The New York Times

Source: NYT

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