In fact, no large-scale studies have uncovered a strong link between running shoe type and running injuries, and there’s no evidence that anything other than weight will affect your ability to run fast, as long as you remember that lighter is almost always better.
Still, there is lots of suggestive evidence that minimalist shoes might influence footstrike, and further evidence that certain kinds of footstrikes (landing on the forefoot, in particular) lead to softer landing patterns, and, perhaps, fewer injuries. But there are big caveats, and the evidence linking loading rates to injuries is mixed.
Testimonials from people running in, and loving, max-cushioned shoes such as the Hoka are hard to ignore, but so far they’re just testimonials. A five-month-long randomized, controlled study of 247 runners published this fall in the British Journal of Sports Medicine uncovered no difference in injury rates between runners who wore soft-soled shoes and those who wore firm-soled shoes. (The researchers did, however, find that body weight and training intensity affected injury rates.) Nor have researchers ever found a strong link between pronation and injury, so it's no surprise that stability shoes don't seem to help people who have been diagnosed as "over pronators." One 2009 paper concluded, famously, that prescribing cushioned, motion-controlled shoes to distance runners was “not evidence-based.”
Likewise for Vibrams and other minimalist shoes. There’s no reason to doubt testimonials of dedicated wearers (I’m one), but it’s important to remember what we know about cushioning: adding or subtracting it just doesn’t significantly affect impact forces or running economy.
How is that possible? Biomechanists have long known that runners automatically “tune” their legs, adjusting muscle tension and knee flexion to keep impact forces within a neurologically determined range. In simple terms, that means people who run in Hokas will land a little harder than they would in less cushioned shoes, and people who run in Vibrams will land a little softer.
Overall, form may matter a lot less than you think it does. In early 2011, I spoke with Dathan Ritzenhein for an article about running form. Ritzenhein, then a three-time Olympian and former American record holder at 5,000 meters, had started rebuilding his form under coach Alberto Salazar. (The experiment was even the subject of an interesting article in The New Yorker.)
Surprisingly, when we spoke, Ritzenhein said that his form was never a huge priority for him, at least not compared to all the other stuff he did with Salazar on a daily basis. "For a year, it was maybe in the top five," he said. "But we always ran 100, 120 miles a week. We lifted. We did intervals. We did long tempo runs. Those were the key things."
So why do we care so much about shoes and form? In part, I think many runners assume that running shoes are like other kinds of gear, and that running technique is like other kinds of athletic technique. If you don’t have a bike, skis, or a surfboard, you can’t go biking, skiing, or surfing. Nor can you do any of those sports very well without the right movement patterns.
But you don’t need shoes to go running, and some of the best runners in history have had terrible form. Overwhelmingly, it seems, success in running is a function of fitness. If biomechanics play a role, it’s probably not a very big role.
That isn’t to say that you shouldn’t be enamored with your shoes or work on your technique. It’s more an argument for perspective: unless you’re dealing with a chronic injury that you’re sure isn’t the result of training errors, your time is better spent crafting the right balance between mileage and intensity, on eating and sleeping well, on strength training and mental toughness. There’s simply not much evidence that you need to worry about shoes.