The participants of the study, aged 40–70 years old, did not have cancer when they underwent the fitness assessment. The study used data on 49,143 health system patients who had undergone exercise tests of fitness between 1991 and 2009.
The investigators found that the fittest individuals had a 77% lower risk of developing lung cancer and a 61% reduced risk of developing colorectal cancer compared to the least fit individuals.
The results also revealed that among individuals diagnosed with lung cancer or colorectal cancer, those with the highest level of cardiorespiratory fitness had a reduced risk of dying during the 8 year follow-up of 44% and 89% respectively.
Estimates suggest that lung cancer caused 154,050 deaths in the U.S. in 2018, which is around 25% of all cancer deaths. Colorectal cancer is the third most common cause of cancer deaths in the U.S.
In conclusion, higher levels of fitness are associated with a lower risk of lung and colorectal cancer in men and women, and a lower risk of all‐cause mortality among those diagnosed with lung or colorectal cancer.