People with high cardiorespiratory fitness are at markedly reduced risk for developing lung cancer, and if they do develop it, they have a lower mortality rate than their counterparts who are not fit, according to an observational study published last year in Cancer. The study found that the same was true for colorectal cancer.
Researchers studied 49,000 people, ages 40 to 70, without cancer who underwent treadmill stress testing to evaluate their cardiorespiratory fitness and were then followed for an average of eight years. Those who were fittest had a 77 percent lower risk of developing lung cancer and a 61 percent lower risk of colorectal cancer than those who were least fit. Age, race, weight, smoking history, and several other factors were controlled for.
Among people who developed lung or colorectal cancer, the fittest had, respectively, a 44 percent and an 89 percent lower mortality rate during the follow-up period than the least fit. People who were only moderately fit also had reductions in these risks, though less dramatic ones.
Cardiorespiratory fitness, which is a measure of your peak energy expenditure, takes into account not only physical activity but also inherited and other factors, such as age and the overall functional health of your organs. Typically, it can help determine cardiovascular disease risk. The study authors noted that further research is necessary to determine whether improving your level of fitness can reduce your cancer risk. In the meantime, there are many other health benefits that accompany better fitness.