Key PointsQuestionIs there an association between cardiorespiratory fitness and colon, lung, and prostate cancer incidence and mortality in Swedish men?FindingsIn this cohort of 177 709 men followed up for a mean of 9.6 years, higher cardiorespiratory fitness was associated with a lower risk of colon cancer incidence. A lower risk of death from lung and prostate cancer was also noted.MeaningThe findings of this study suggest that cardiorespiratory fitness may have a potentially important role in reducing the risk of developing and dying from certain cancers in men.