He has only one leg, but grinder Umberto Panerai jumps when Prada jumps. He has to — the Olympic medallist drives the fitness regime for the Italian America’s Cup crew and he feels he must set an example. Panerai, 47, an Italian waterpolo hero, wears a plastic leg after an accident with a concrete mixer 10 years ago.

Sailing on the Luna Rossas as a backup grinder, Panerai has no desire to make the No 1 lineup and sail in the Louis Vuitton Cup final against AmericaOne next week. “I have spent two years on these boats, and I have never slipped over. But it will happen one day — during a race — and that would be bad,” he said. “I know how much time and energy these guys have put into it to get where they are.”

Panerai’s priority is to keep the Prada sailors at peak fitness as they wrestle with the temperamental Cup boats. For 17 years, Panerai was at the top of the Italian waterpolo world. He played goalkeeper for the national side at three Olympic Games — winning a silver medal in 1976. In 1990 he was coaching a team in the south of Spain, and selling concrete mixers, when he suffered the life-altering accident. “I was dismantling my stand at a show when a 6000kg mixing machine fell on top of me and crushed my foot. At the emergency room, the young doctor was afraid of a bubble in my bloodstream so he cut the foot off.”

Seven operations later Panerai had lost most of his lower right leg as doctors whittled the bone away trying to fit an artificial foot. He had to fight a morphine addiction but three months after the accident he was out sailing. He is not bitter about losing a leg. “You cannot change your destiny. Every day you are testing yourself to discover what you can do. I think sailing is fantastic. When you leave the dock and go to sea it’s like washing the brain.” His job began two years ago when he was sailing with Prada boss Patrizio Bertelli, who asked him to draw up a fitness programme for the crew.

Bertelli then offered him a job with the syndicate, but Panerai took four months to say yes. “I was just married for a second time, we had a little baby, a daughter in Spain, a nice house in Tuscany and a dog. We were being asked to stop everything and start again,” he said. “But this was such a big opportunity for me.” The Prada sailors have gained a reputation as being one of the fittest crews on Syndicate Row, thanks to Panerai’s motivation. They work every morning in the gym they have set up inside the Heritage Hotel. “It wasn’t easy in the beginning. A lot of them didn’t know what a gym was,” he said. “Now they can be coach of themselves.”