Every second counts for elite runners competing in races whether sprints or marathons. Eyebrows were raised therefore in 2017 when Nike introduced their advanced running shoe technology shoes. Would they significantly affect performances in professional sports?
A new study has shown that they do indeed reduce running times for runners. The study looked at seasonal best times for professional male and female runners in 0 kilometers, half marathon and marathon races between 2012 and 2019.
A statistically significant decrease in race times after 2017 coincided with the introduction of the Nike Vaporfly 4%.
Female elite athletes received the most benefit from the shoes which correspond with a decrease in seasonal best times from 1.7 to 2.3 percent. Men also showed a decrease of 0.6 to 1.5 percent for the boys.
For marathons the technology improved female marathon time by about 2 minutes and 10 seconds equating to a 1.7 percent boost in performance.
Exactly how the improvements in performance occur is still a mystery.
One advantage is that it uses the latest kind of lightweight foam within the midsole. This provides the runner with a greater energy return. There is also a plate within the midsole which also contributes to maximizing energy return with each step. What has been found is that the shoe propels the runner forward with less effort on their behalf.
The statistical gap between genders is possibly explained by the difference in weight between the sexes. Women are generally lighter so benefit more from a greater rebound effect. Their slightly different running pattern compared to men is augmented by how the shoe technology works.
Additional research is also being considered to find out whether the shoes also reduce the chance of injuries.
Critics of the shoes say that they give the wearer an unfair advantage with some athletes claiming that they should be banned. Kenya´s Tegla Loroupe believes it counts as cheating as athletes are not using all their own strength. She goes on to say that it gives an advantage to those who can afford the shoe and compares it to doping.
Welsh marathon runner Dewi Griffiths told BBC Sport that the shoes were essentially giving runners free time in races. Back in 2020, the World Athletics organisation tightened their rules around high-tech shoes. This included banning the Nike ‘Alphafly’ prototype shoes. Eliud Kipchoge wore these when he became the first athlete to run a marathon in under two hours in 2019.
Nike has come out and said it respects the spirit of the rules and doesn’t believe they are creating anything that returns more energy than the runner expends.
Aside from running shoe technology other companies are using new materials and innovations. These include the british sportswear brand Inov-8. They have created a range of graphene enhanced shoes ranging from hiking boots to trail running shoes. Graphene-infused foam has been proven to deliver an increase of 25% in terms of energy return.