People receiving cancer treatment might want to consider taking more outdoor exercise.
According to recent comments from Professor Tim Oliver, founder of the male cancer charity Orchid, brisk walking out of doors can offer health benefits.
He explained: "It is possible that one of the main ways that exercise prevents cancer is that, as it is mostly outdoors, the patients whose cancers grow slower do so because they have higher vitamin D levels.
"These enable the body to better resist minor infections that get into the prostate at any time of life, from puberty onwards."
Earlier this month, research from the University of California identified a link between brisk walking and a lower risk of prostate cancer progression.
Men who walked for at least three hours a week at a minimum speed of three miles an hour were 60 per cent less likely to develop biochemical markers of cancer recurrence or need a second round of treatment for the disease.