Cardiorespiratory fitness and cancer incidence in men.

Purpose: The preventive role of cardiorespiratory fitness (CRF) in cancer is not well established. The present study sought to evaluate the association between CRF and cancer incidence in men.

Methods: Maximal exercise testing was performed in 4920 men (59.2 ± 11.4 years) free from malignancy at baseline who were followed for 12.7 ± 7.5 years. Relative risks and population attributable risks were determined.

Results: During the follow-up, 25.8% were diagnosed with any type of cancer. CRF was inversely associated with total cancer incidence; for each one metabolic equivalent increase in CRF, there was a 4% reduction in cancer incidence (P < .001). Compared with low CRF, moderate and high CRF levels were associated with 14% (95% CI [0.74-0.99]) and 26% (95% CI [0.62-0.89]) reduced risks for all cancers, respectively (P for trend = .004). Low CRF had a population attributable risk of 3.0% for cancer incidence. The associations between CRF, prostate, skin and colorectal cancers were not significant.

Conclusions: Higher CRF is associated with lower total cancer incidence in men. A novel finding suggests that eliminating low CRF as a risk factor would potentially prevent considerable cancer morbidity and reduce the societal and economic burden associated with cancer. These findings underscore the importance of CRF for primary cancer prevention.