Cancer Protective Effects of Exercise

Reflecting the ability of the body’s circulatory and respiratory systems to supply oxygen to the skeletal muscles during sustained physical activity, cardiorespiratory fitness (CRF) can be improved by regular exercise.  Susan G. Lakoski, from the University of Vermont (Vermont, USA), and colleagues assessed 13,949 men, who were diagnosed with and survived cancer at age 65 or older. Subjects underwent a fitness exam at the study’s start, with CRF assessed via treadmill test.  The team followed the participants’ fitness levels and surveilled for incidences of cancer diagnosis.  The researchers found that high CRF in midlife associated with a 55% lower risk of lung cancer, and a 44% lower risk of colorectal cancer, as compared to men with low CRF.  Further, the team observed that high CRF in midlife associated with a 32% lower risk for cancer death among men who developed lung, colorectal or prostate cancer at age 65, as compared with men with low CRF.  Finally, a high CRF in midlife linked to a 68% reduction in cardiovascular death, as compared with low CRF among men who developed cancer.  Observing that: “There is an inverse association between midlife [cardiorespiratory fitness] and incident lung and colorectal cancer but not prostate cancer.,” the study authors conclude that: “High midlife [cardiorespiratory fitness] is associated with lower risk of cause-specific mortality in those diagnosed as having cancer at [age 6