'Spray-on' running shoes could shake up Olympics

Forget about spray-on hair and spray-on dresses. Now we have marathon-winning spray-on shoes.

Swiss sportswear brand On is the latest company to embrace spray-on materials with a robot-made sneaker it believes can improve performance at this month’s Olympics.

The Cloudboom Strike LS is lace-free and weighs less than the latest iPhone. Designed to be more adaptable, dynamic and supportive than your average running sneakers, the US$330 shoes already have a convincing track record: Kenyan runner Hellen Obiri, an Olympic silver medalist and the only woman to have won indoor, outdoor and cross-country world titles, triumphed at this year’s Boston Marathon wearing a pair. She will don them again to compete at the Paris 2024 Games.

Olympians have already raced in the sneaker, and more are expected to wear them during the Games. File photo

Zurich-based On credits its shoes’ success to a combination of biomechanics, physiology and extreme lightness. A men’s U.S. size 8.5 weighs just 170g per shoe, over 100g lighter than several popular running shoes of the same size. “More than anything, we want the athletes to win,” said senior director of innovation, Ilmarin Heitz, in a promotional video published last week. “That is our gauge of success.”

With no heel-cap, laces or tongue, the translucent, sock-like sneaker looks like a running shoe that has shed its skin. Its inventor, Johannes Voelchert, came up with the idea as a student after seeing a Halloween-themed hot glue gun that shot decorative spider webs.

“I saw that there was a quick way of creating a textile onto a complex shape,” Voelchert, now On’s senior innovation concept designer, said in the brand’s video. “A shoe seemed to be the right object.”

Voelchert brought his idea to the Milan Design Fair, where he caught the Swiss sportswear brand’s attention. According to On, the shoe’s uppers (the material above the sole) are made from a type of thermoplastic and colored and branded in three minutes using just a robotic arm. The upper is sprayed in one go and can be attached to the carbon-fiber and foam rubber sole using heat, not glue.

The company claims its technology reduces the carbon emissions of producing a shoe’s upper by 75%, compared to its other sneaker models. The material, which it dubs LightSpray, has “the potential to move us towards a more sustainable future,” said On’s co-CEO Marc Maurer.

The technology will be on display at a pop-up in Paris later this month as people flock to the French capital for the 2024 Olympics. And while it is not yet known which athletes other than Obiri will wear them at the Games, a number of Olympians have recently raced in the Cloudboom Strike LS, including Australian middle-distance runner Olli Hoare.

The brand said that it hopes athletes going to Paris who have previously worn the shoes — such as Irish 1,500-meter runner Luke McCann — will continue to choose them this summer.

On is not the first company to experiment with spray-on textiles. In October 2022, luxury French fashion house Coperni made headlines when it sprayed a custom-fit dress onto model Bella Hadid at Paris Fashion Week. The label partnered with Manel Torres, whose brand Fabrican has been producing “clothes-in-a-can” for over 20 years. Spray-on fibers have also been used in the beauty industry, with “hair in a can” solutions used to conceal bald spots and thinning hair.

Having initially been made available to the public in April, the Cloudboom Strike LS will go on sale again later this year.