# Cardiorespiratory fitness

Cardiorespiratory fitness (CRF) is how well your heart, blood vessels, and lungs deliver oxygen to your muscles during sustained activity. It is most often measured as VO2max. CRF pulls together several things. They are your lung function, your cardiac output, your vascular health, and your muscle's ability to use oxygen. Some large cohort studies found something striking (for example, Mandsager et al. 2018). Low CRF can carry a death risk as big as coronary artery disease, smoking, or diabetes. Sometimes even bigger. That makes CRF a powerful predictor of your longevity, and one you can change.

## Sources

- Kodama S, Saito K, Tanaka S, Maki M, Yachi Y, Asumi M, Sugawara A, Totsuka K, Shimano H, Ohashi Y, Yamada N, Sone H. (2009). Cardiorespiratory fitness as a quantitative predictor of all-cause mortality and cardiovascular events in healthy men and women: a meta-analysis. JAMA. https://doi.org/10.1001/jama.2009.681
- Mandsager K, Harb S, Cremer P, Phelan D, Nissen SE, Jaber W. (2018). Association of Cardiorespiratory Fitness With Long-term Mortality Among Adults Undergoing Exercise Treadmill Testing. JAMA Network Open. https://doi.org/10.1001/jamanetworkopen.2018.3605

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_Canonical: https://longevity-switzerland.com/en/glossary/cardiorespiratory-fitness · Part of Longevity Cities · Updated 2026-06-22_