Davidson T, et al. – An association of both cardiorespiratory fitness (CRF) and physical activity (PA) with mortality has been established but it remains unclear if they are associated with all–cause mortality independent of each other. In this current study, it was shown that PA was associated with mortality independent of established risk factors, but not CRF in adult men. Conversely, CRF strongly predicted mortality, independent of PA status and established risk factors.

Methods

• Researchers assessed CRF by a maximal exercise test and PA by self-report in 8171 male veterans.
• They assessed the predictive power of CRF and PA, along with clinical variables, for all-cause mortality during a mean (±SD) follow-up 8.7 (4.4) years during which there were 1349 deaths.

Results

• Findings demonstrated that CRF was associated with mortality after adjusting for clinical variables, and remained a strong predictor of mortality after further adjusting for PA (HR: 0.85; 95% confidence interval [CI]: 0.83 – 0.87).
• Researchers observed that PA was a significant predictor of mortality after controlling for clinical variables, however the association was eliminated after further adjusting for CRF (HR: 0.98; 95% CI: 0.88 – 1.10).
• In CRF stratified analysis, it was revealed that being active (≥150 min/week) was not associated with mortality within the unfit or fit categories (p>0.4).
• However, PA stratified analysis demonstrated that subjects categorized as fit (≥7 METS) had a lower relative risk of mortality regardless of PA status (p<0.001).