Adults with the highest cardiorespiratory fitness levels have a reduced risk for lung and colorectal cancer—and a lower risk of death if they do develop the cancers, according to findings from a study published in Cancer.

Researchers evaluated 49,143 cancer-free adults aged 40–70 years who participated in clinician-referred exercise stress tests from 1991–2009. They measured cardiorespiratory fitness in metabolic equivalents of task (METs) in four classifications: less than 6 (reference), 6–9, 10–11, and 12 or higher.

After adjusting for age, race, body mass index, smoking history, and presence of diabetes, the researchers found that participants with METs of 12 or higher had a 77% lower risk for lung cancer and 61% lower risk for colorectal cancer. Those who did develop the cancers had a 44% lower risk of dying from lung cancer and an 89% lower risk of dying from colorectal cancer.

The authors suggested that fitness testing may useful in assessing risk for lung and colorectal cancer.