For years, studies of the effect of exercise on prostate cancer delivered mixed results. Some showed that it decreased the chances of getting prostate cancer; some showed no relationship. Now, from Harvard”s Chan School of Public Health, comes evidence that men who routinely do vigorous exercise have a 30 percent lower risk of developing advanced prostate cancer and 25 percent lower risk of developing lethal prostate cancer. The new study looked at data from 49,160 men between the ages of 40 and 75 who enrolled in The Health Professionals Follow-up Study in 1986 and were followed to 2012. The men responded to biennial questionnaires that included questions about diet, health, and physical activity. On average, men in the highest category of vigorous activity engaged in an equivalent of 25 minutes day of running, bicycling, swimming, heavy outdoor work, and playing sports such as tennis or racquetball.