The Mawem Brothers may be the stars of French climbing, but their real impact is being felt on the ground. We’re hardly five minutes into our conversation at a climbing centre in Salt Lake City before a superfan of the medal-winning siblings interrupts to ask for a selfie. The younger brother, 30-year-old Mr Mickaël Mawem cheerily obliges, but rather than just taking a quick snap, he talks to her for an emotionally charged few minutes.

“She broke into tears and said, ‘You changed my life. Seeing that it’s possible is thanks to you,’” he says, explaining that the young African-American woman told him that seeing black people at the top of a predominantly white sport had inspired her to get into climbing. She now works at a climbing centre.

Mickaël and his brother, Mr Bassa Mawem, 36, are two of only a few black athletes performing at elite level of the sport. But their presence – with more than 100,000 Instagram followers – is inspiring a much more diverse uptake of speed, bouldering and lead climbing. Their lively posts, in which they demonstrate jaw-dropping, Spidey-style physical abilities (seemingly running up walls and miraculously hanging off holds by their fingertips), show off the sport at its most playful and powerful. Their hyper, open energy is drawing in a new crowd to a pursuit that’s too often seen as insular, dour and smelly shoed.

“Today, the representation of climbing is much more dynamic,” says Bassa. “When we put up a video, it encourages people to find out more. We’re starting to get people interested.”

The brothers’ entry into climbing was completely par hasard. After growing up in French Guiana, Nîmes and Cameroon, the brothers finally settled in Alsace when their mother remarried. It was there, as a 15-year-old, that one of Bassa’s friends invited him to try out climbing in a lunchtime sports session. He was hooked and soon had his younger brother following suit.

“We used to go every day of the week,” Mickaël says. “We were obsessed. Right away, we put everything into it. The first year, we entered a little competition and came last, so we said, ‘Never again!’ We wanted to be the best, even if we didn’t know the level we needed to be at.”

They set up a mini climbing wall and gym in their cellar at home so they could train every day. “We didn’t have much in our lives, but everything we did have, we took full advantage of and did it thoroughly.”

Two decades into the sport and their brotherly bond is still incredibly strong. Their relationship has helped push them to a slew of French, European and world medals and kept them in the national team for considerably longer than average.

“We motivate each other,” says Bassa. “If one day I’m tired and I want to stop, my brother will say, ‘Come on! Carry on!’ People often ask me who my idol is and I say it’s my brother.”

Even when they have to face each other in competition, the bond still can’t be broken, Mickaël says. “Me and my brother have always been united. We’re always together. We train together. We live together. We do rock climbing in pairs. We are like one with our training, with our competitions, with life. It’s essential that both of us succeed.”

Energetic and enterprising, the brothers are also looking to success beyond competition. They’re opening a climbing wall in Strasbourg in September and hope to open more across France and globally. “Alsace is where we started to climb, started our story, so we wanted to start there,” says Mickaël.