At age 70, Alfred Roberts plays hockey twice a week. Nothing special, right? Except that for three years he has had advanced prostate cancer, which has spread to his bones. "I've always been active.

Exercise is well known to bring health benefits. But it has now been found to cut deaths from cancer even when people get fit after their diagnosis – and it can have as much benefit as chemotherapy.

A randomized crossover pilot study conducted by researchers at the University of Sherbrooke and the Research Centre on Aging in Quebec, Canada ...