A month before the biggest athletics event of the year, a dizzying number of speed performances lit up local and professional meetings.
In the spring, the University of Washington track team produced eight miles under four minutes. In June alone, four high school runners broke that barrier in the same race. On the professional circuit, three world records were broken in one week in Paris in June: Kenya’s Faith Kipyegon set a new record in the women’s 1,500 meters and 5,000 meters, and Ethiopia’s Lamecha Girma set a new record in the men’s 3,000 meters steeplechase.
On Friday night, Kipyegon set yet another record, breaking the one-mile women’s world record by nearly five seconds when she broke the ribbon in 4 minutes, 7.64 seconds. The performance surprised track fans used to records that usually improve by mere tenths of a second.
The question – why so many fast times? – was asked and answered endlessly. Wavelight, the pace-setting technology, certainly helps. So do the ever-evolving breeds of supershoes – those thick, springy kicks with a midsole plate that have revolutionized running in recent years, delivering greater rebound energy when a runner takes the plunge.
But many sports scientists see something else: the payoff of years of training in those specialized shoes. And it’s a sport that recreational runners can benefit from too.
“Since shoes are a new tool, the more we run in them, the better we adapt,” said Geoff Burns, a physiologist and biomechanics expert at the US Olympic and Paralympic Committee.
Burns and other sports scientists have unshakable faith in what’s known as the principle of specificity: for a runner to compete at his best, he needs to train the same way he’s going to run. That means running at race pace, drinking the same fluids, consuming the same gels and, perhaps most importantly, wearing the same shoes.
Supershoes arrived on the scene in 2016 when Nike shocked the world with its first thick-soled, energy-returning shoe, the Nike Zoom Vaporfly 4%. They were so obviously faster than previous shoes that World Athletics, track and field’s governing body, began limiting a shoe’s midsole height in 2020. Now every major shoe company has supershoes in their lineup, and hundreds of thousands of everyday runners wear them.
For elite athletes, it has become difficult to resist the lure of training and running in super tennis. Lindsay Flanagan, who has a personal best marathon time of 2:24:43, will be one of three Americans to run the World Championship marathon in Budapest in August.
“Since I’m going to be wearing super shoes in the races, I want to get a good feel for them in practice,” Flanagan said. “I have found that I can log more quality days as well as more mileage overall because my legs recover sooner.”
But Flanagan also knows some professional runners who don’t train in super shoes. They believe they can increase their strength by wearing traditional shoes, then gain an extra boost on race day by putting on the improved shoes.
Of course, the “Nietzsche principle” can sometimes be applied: what doesn’t kill you makes you stronger. A recent pilot study from California State University, East Bay found some evidence for this, comparing the fitness gains of runners in traditional running shoes compared to supershoes. Those who wore flats complained of more muscle soreness, but they also improved their running economy more than runners who wore supershoes.
Two experts in the study of running injuries, Adam Tenforde and Amol Saxena, believe that wearing supershoes can lead to serious illness. In February, they co-authored a paper in the journal Sports Medicine that featured five case studies of navicular bone injuries from wearing supershoes.
“I’ve seen supershoe injuries in runners at all levels – high school runners, recreational runners, and elite athletes,” Saxena said. “Shoes can place unusual stresses on bones and soft tissue structures.”
On the other hand, there are no known reviews of injury rates in supershoes that follow standard statistical models. And two leading supershoe researchers, Wouter Hoogkamer and Max Paquette, say they haven’t seen convincing data that runner’s biomechanics are dramatically different in supershoes than in traditional shoes.
Both Burns, the physiologist, and Dustin Joubert, an exercise physiologist at Stephen F. Austin State University, also found that, contrary to the assumptions of many, supershoes have a longer functional life than traditional ones. They found that the supershoes’ dense foam midsoles retain their cushioning and energy-returning properties longer than the softer EVA midsoles of previous shoes.
The plush cushioning of supershoes can also be a boon for older runners. Bill Salazar, a 77-year-old runner from Arizona, has been training on them for more than three years, running about 35 miles a week.
“The big benefit for me is that I recover faster with super shoes,” said Salazar, who ran a 4:22 marathon in Berlin last September.
The same cushioning and recovery benefits have been reported by many top runners. They note that they used to “hit the wall” after 20 miles in the marathon, but now, wearing supershoes, they can finish stronger and faster because their leg muscles aren’t as tired.
At the London Marathon in April, Kenyan rookie Kelvin Kiptum wore supershoes as he clocked the marathon’s second-fastest time of 2:01:25. Kiptum ran the first 13.1 miles in 1:01:40 and the second leg in 59:45.
Apparently, her legs weren’t too tired.