Cardiorespiratory Fitness (CRF) Lowers Cancer Risk

A well-established, graded, inverse association exists between cardiorespiratory fitness (CRF) and risk of cardiovascular disease (CVD) as well as all-cause mortality in numerous healthy and clinical adult populations.1- 3 Compared with those classified in the lowest CRF category (<7.9 metabolic equivalents [METs]), individuals in the highest CRF category (?10.9 METs) have a 1.6- to 1.7-fold lower risk of CVD and all-cause mortality, respectively.4 Accordingly, measurement of CRF via formalized exercise testing provides a wealth of diagnostic and decision-making information in cardiovascular medicine.

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... there is growing evidence that lifestyle behaviors performed years, even decades, prior to a cancer diagnosis may influence outcomes after diagnosis. Indeed, midlife body mass index (BMI) and physical activity are predictors of cancer-specific as well as all-cause mortality in multiple cancer diagnoses.15- 21 To our knowledge, no study to date has investigated whether objective measures of exercise exposures (ie, CRF) in apparently healthy persons at midlife is predictive of primary risk of cancer as well as cause-specific mortality in those who are subsequently diagnosed as having cancer. Prediction of cause-specific mortality after a cancer diagnosis is becoming increasingly important given that individuals diagnosed as having certain forms of cancer now have sufficient survival to be at risk for noncancer competing causes of mortality, primarily CVD, owing to the chronic and late effects of treatment.

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In the current study, high CRF conferred a 55% and 44% reduction in the risk of lung and colorectal cancer, respectively, compared with low CRF. Every 1-MET increase in CRF was associated with 17% and 9% relative risk reductions in lung and colorectal cancer risk, respectively. These results are similar to those of the Kuopio Ischemic Heart Disease Risk Factor Study,34 which found that a 1-MET increase in CRF was associated with a 20% and 12% reduction in the relative risk of lung and colorectal cancer, respectively, in 2268 asymptomatic Finnish men. Interestingly, in contrast to lung and colorectal cancer, high CRF was a risk factor for prostate cancer even after adjusting for potential confounding variables. The current results are similar to those of 2 other studies in the literature on CRF and prostate cancer. Laukkanen et al34 found that a 1-MET increase in CRF was associated with a nonsignificant increase in prostate cancer risk (HR, 1.03; 95% CI, 0.94-1.12), Byun et al,6 using data from the Aerobics Center Longitudinal Study, found that compared with men in the lowest CRF category, those with moderate or high CRF had adjusted HRs of 1.68 (95% CI, 1.13-2.48) and 1.74 (95% CI, 1.15-2.62) for incident prostate cancer, respectively.

From Time Magazine article on the study:

Here’s the best part: it doesn’t take a lot of exercise to have a big health impact, Lakoski found. “Just a small improvement in fitness made a difference in survival of those that developed cancer,” she says. Compared to men who could run 12-minute miles on the treadmill at age 50, men who ran slightly faster 11.5-minute miles had an additional 10% decrease in cancer death and an extra 25% decrease in cardiovascular death among those who developed cancer in the study.