TOKYO: Athletes scampered up giant walls and clambered over plastic boulders as climbing made its Olympic debut on Tuesday, taking the sinew-straining, muscle-bulging sport to dizzying new heights. Twenty climbers competed in the men’s qualifying round, testing their mettle over the three disciplines of speed, lead and bouldering. South Africa’s Christopher Cosser and South Korea’s Chon Jong-won kicked off the opening speed round, where climbers race up a 15-metre (50 feet) vertical wall using a series of plastic holds. Under a setting sun on the outside wall, Cosser zipped to the top in 6.48 seconds, while Chon slipped near the start and spun back down on his safety rope. “It’s kind of surreal,” said Cosser. “It’s been a dream of mine since I was a little kid, so to fully experience it is phenomenal.” The combined score of the three events determined the final positions, with eight climbers going through to the final round. France’s Mickael Mawem finished first, followed by Japan’s Tomoa Narasaki and 17-year-old American Colin Duffy. The bouldering round saw climbers try to “solve” four short courses without a rope, making dramatic leaps and hauling themselves around with impressive strength. In lead climbing, they clipped hooks along the face of a 15-metre wall, trying to climb as high as they could. “It was a wild experience to try to be here and not go crazy with nerves, but I made it through so I’m happy to be done,” said American Nathaniel Coleman, who qualified in eighth. “You’re pretty tired by the end of the day but you only have one climb left to do. You turn off all the pain and turn off all the hurt and you just go.” ‘Forget the sweat and grease’: But the conditions took their toll on the climbers, with Narasaki opting out of one of his two speed runs and a bouldering course to save wear and tear on his fingers. The humidity of Tokyo’s sweaty summer also caused problems. “We know all these holds, and we know how it should feel,” said the Czech Republic’s Adam Ondra. “It feels like you’re just sliding off — you just don’t feel comfortable on a wall. You just have to forget about the sweat and grease and keep going.” Ondra is known as one of the world’s best bouldering and lead climbers, but he admits he is “definitely not talented” at the speed event. The Olympic format has been criticised in some quarters as a mish-mash of different climbing disciplines. “It’s like getting track athletes that have always just been single-discipline athletes to suddenly do the shot put, the 100 metres and the 15,000 metres,” said Australia’s Tom O’Halloran. “Everyone here are mostly specialists in different things, so that adjustment was tricky.” Ondra — the sport’s biggest star — said there are so many types of climbing that describing someone as the best in the world is “kind of nonsense”. “But definitely whoever wins will be the best climber that day, and the first Olympic champion. That’s something you can’t take away,” he said. The women’s qualifying event, featuring hot favourite Janja Garnbret of Slovenia, takes place on Wednesday.