As America’s leading endurance sports coach, Joe Friel, 71, has many reasons to be interested in the toll that ageing takes on fitness. He is an elite triathlon and cycling instructor, has coached sportspeople of all ages and abilities, and is the author of more than a dozen books for athletes including the bestselling Training Bible series. His curiosity about whether people can extend their sporting activities into the decades beyond middle age also has personal resonance. “I was approaching my 70th birthday and I was wondering what to expect. The number was scary because of the drop in fitness and performance that’s supposed to happen,” he says.
For the fitness enthusiast, growing old can be particularly tough. After a lifetime of being active, suddenly