Cardiorespiratory fitness, physical activity and cancer mortality in men

The preventive role of cardiorespiratory fitness (CRF) and physical activity (PA) in cancer mortality is not well-established. This study sought to evaluate the association between CRF, PA and cancer mortality in men. Maximal exercise testing was performed at the VA Palo Alto Health Care System in 5876 male veterans (60.5 ± 11 years) free from malignancy at baseline who were followed for mean of 9.9 (range 0.11 to 26.8) years. PA status was assessed in a sub-group of 4034 participants. Relative risks and population attributable risks (PAR%) for cancer-related mortality were determined. During the follow-up, 447 men (7.6%) died from cancer. Forty-nine percent of the sample was considered physically active (defined as meeting the minimal PA guidelines); this group exhibited a 20% reduction in cancer mortality risk [95% confidence interval (0.67–0.97), p = 0.02]. CRF was inversely associated with cancer death. For each 1 MET increase in CRF there was a 5% reduction in risk for cancer mortality (p = 0.01). Compared to the least fit group (< 5.0 METs), subjects with moderate to high CRF exhibited 26–46% reduced risks of cancer mortality (p for trend = 0.002). The PARs% for low CRF and inactivity were 6.6% and 8.5%, respectively. Moderate and high CRF levels and meeting the minimal PA guidelines have protective benefits against cancer mortality in men. Eliminating inactivity and low CRF as risk factors could potentially prevent a considerable number of cancer deaths and reduce the associated societal and economic burden.