Exercising vigorously more than 3 hours per week reduces chance of dying from prostate cancer.

2,705 men diagnosed with prostate cancer were followed for 18 years. This study evaluated the relationship between exercise levels and prostate cancer survival. They found that men who exercised vigorously for 3 or more hours per week had a 49% lower risk of all-cause mortality (dying from anything) and a 61% lower risk of dying from prostate cancer when compared with men who exercised vigorously for less than 1 hour per week. Men who exercised vigorously before and after diagnosis had the lowest risk of death.

Kenfield, S. 2011

https://www.ncbi.nlm.nih.gov/pubmed/21205749