You should act your age – at least when it comes to exercise. Here’s why

Many people approach their physical fitness as if they were a decade or two younger. Composite: Ana Galvañ/The Guardian

Last year, I had to give up running. It was, as my sports medicine doctor counseled, “time”.

Since I was a teen, it had been my primary form of exercise and stress relief. But for months, I had been ignoring small signs of encroaching decrepitude: the popping and grinding in my right knee and hip joints whenever I stood up, bent down or took the stairs. The medical term for this is crepitus, yet I kept stubbornly persuading myself that I was still a “young” fiftysomething.