The real power of super shoes could be supercharged training

NEW YORK – One month before the year’s biggest track and field event, a dizzying number of fleet-footed performances have lit up professional meets.

Three world records were shattered within a week in Paris in June – Faith Kipyegon of Kenya set a record in the women’s 1,500m and 5,000m, and Lamecha Girma of Ethiopia set a new mark in the men’s 3,000m steeplechase.

Last Friday night, Kipyegon set yet another record, smashing the women’s 1-mile (1.6km) world record by almost five seconds when she broke the tape in 4min 7.64sec.

The question – why so many fast times? – has been asked and answered endlessly. Wavelight, the pace-setting technology, surely helps. So do the ever-evolving breeds of super shoes – those thick, springy kicks with a midsole plate that have revolutionised racing in recent years by giving higher rebound energy when a runner pushes off.

But many sports scientists see something else – the payoff from several years of training in those specialised shoes.

“Because the shoes are a new tool, the more we run in them, the better we adapt,” said Geoff Burns, a physiologist and biomechanics expert with the US Olympic and Paralympic Committee.

Burns and other sports scientists have an abiding faith in what is known as the specificity principle – for runners to compete at their best, they have to train in the same way they will race. That means running at their race pace, drinking the same fluids, consuming the same gels, and, perhaps most important, wearing the same shoes.

Super shoes burst onto the scene in 2016 when Nike shocked the world with its first thick-soled, energy-returning shoes, the Nike Zoom Vaporfly 4%. They were so obviously faster than earlier shoes that World Athletics began limiting the height of a shoe’s midsole in 2020. Now all major shoe companies have super shoes in their lineup, and hundreds of thousands of everyday runners are wearing them.

For elite athletes, it has become hard to resist the pull of both training and racing in super shoes.

Lindsay Flanagan, who has a personal best marathon time of 2:24:43, will be one of three US women running the World Championships marathon in Budapest in August.

“Since I’m going to be wearing super shoes in races, I want to get a good feel for them in training,” she said. “I’ve found that I can log more quality days, as well as more mileage in general, because my legs come around sooner.”

But Flanagan also knows some professional runners who do not train in super shoes.

They believe they can build up their strength while wearing traditional shoes, and then gain an extra boost on race day by slipping on the souped-up shoes.

A recent pilot study from California State University found some evidence for this by comparing runner fitness gains in traditional racing flats compared to super shoes. Those who wore the flats complained of more muscle pain, but they also improved their running economy more than runners who wore super shoes.

Two experts in the study of running injuries, Adam Tenforde and Amol Saxena, believe that super-shoe use can lead to serious ailments. In February, they co-authored an article in the journal Sports Medicine that presented five case studies of navicular bone injuries that stemmed from super-shoe use.

“I’ve seen super-shoe injuries in runners at all levels – high school runners, recreational runners and elite athletes,” Saxena said. “The shoes can put atypical stresses on the bones and soft-tissue structures.”

On the other hand, there are no known reviews of super-shoe injury rates that follow standard statistical models. And two leading super-shoe researchers, Wouter Hoogkamer and Max Paquette, say they have seen no convincing data that runner biomechanics are dramatically different in super shoes than in traditional ones.

Both Burns, the physiologist, and Dustin Joubert, an exercise physiologist at Stephen F. Austin State University, have also found that super shoes have a longer functional life than traditional ones.

The dense foam midsoles in super shoes, they found, retain their cushioning and energy-return properties longer than the softer ethylene vinyl acetate midsoles in earlier shoes.

Many top runners note that they used to “hit the wall” after over 30km in the marathon, but now, while wearing super shoes, they can finish stronger and faster because their leg muscles are not so fatigued.

In the London Marathon in April, Kenyan newcomer Kelvin Kiptum wore super shoes while recording the second-fastest marathon time, 2:01:25. Kiptum ran the first half in 1:01:40, and the second leg in 59:45.

Apparently, his legs were not very tired.

NYTIMES