Running used to be the most accessible sport available. Rowing was for those who could afford it, cricket required weekends free for long days spent on the field along with a bag containing pads, a bat, a helmet and let’s not forget the most important piece of equipment: the box. Running however, just needed your heart and your lungs. Some proclaimed the importance of a decent pair of sneakers, but others simply went barefoot, trading road for wet sand on beaches or trying their luck on grass or trail. But in recent years, running has become all about the shoes and with the likes of sportswear giants like Nike and Asics doing all they can to revolutionise the technology of running shoes, you’ll have to dig deep into your pockets simply to keep up with the latest trends.
You’ve likely heard of the Vaporfly, which has managed to push aside doubts previously held by runners which saw cushioning not hailed as the protector against injury, but rather something that could lead to greater risk of injury. These heavily-cushioned running shoes from Nike and other brands have steamrolled previous models that did away with most cushioning. Despite barefoot runners speaking out against them, rock up to a Park Run or road race and you’ll find everyone seems to be sporting them.
As Alex Hutchinson writes for Outside, many remained sceptical of cushioned shoes for years. This was largely a result of the barefoot and minimalist running movement, despite the fact there was no evidence to support their claims. “Elements like raised heels, pronation control, and thick midsoles might make intuitive sense, bare footers argued, but no one had ever tested their injury-prevention benefits in properly administered randomised trials.”
Now, research points overwhelmingly to the benefits of cushioning and shoe materials and construction as a means of reducing running injuries. In a study published in the European Journal of Sport Science by Laurent Malisoux of the Luxembourg Institute of Health, researchers were finally able to control the placebo effect in the study by partnering with the French sporting-goods giant Decathlon to produce a number of custom running shoe designs that are visually indistinguishable from the other, differing only in a single technical detail for each trial. It means that participants weren’t able to tell whether they were given a cushioned sneaker or something lacking all support, and wouldn’t therefore experience the emotional reaction that could affect their running and perception of aches and pains.
Blind studies were run, with both the subject and researcher not knowing which type of shoe is being worn. One study found that shoes limiting pronation (an inward rolling motion as your foot strikes the ground) reduced injury risk, while another found that heel-to-toe drops ranging from zero to ten millimetres had varying effects depending on the distance accumulated over the week by subjects.
But in the latest study which analysed shoe cushioning with two Decathlon-manufactured prototypes given to participants – each with an inch-thick layer of midsole cushioning made from EVA foam, only for half to have firmer foam and the other soft foam – it was found that those given the firmer shoes were 52 per cent more likely to develop an injury during the follow-up period, thereby confirming that injury protection is offered from soft cushioning.
Still, it was perplexing because despite reducing injuries, stride pattern indicates that greater cushioning sees runners smack the ground harder. Assessing biomechanics shows that there are two distinct impact forces: that of the lower leg decelerating abruptly as your foot strikes the ground, and the other is the larger force delivered to the rest of the body. They found that soft cushioning slows down the first jolt, spreading it over a longer period of time and causing it to overlap with the second. It means that the total force then applies greater than it is, creating an illusion that softer shoes produce more force.
Ultimately though, it comes down to the runner’s own preferences. Malisoux himself believes we know little about the complex link between shoes and injury and offers the advice to simply stick to the shoes you feel comfortable running in.