Middle-aged men who have a high fitness level may have a lower risk of lung and colorectal cancer, but not prostate cancer. Being fit could also help older men survive cancer if diagnosed later in life.

In the past, researchers have primarily focused on the link between cardiorespiratory fitness (CRF) and cardiovascular disease (CVD), but little research has been conducted on how CRF influences cancer risk, the JAMA Network Journals reported.

The study looked at 13,949 men who had a baseline fitness exam determining CRF through a treadmill test. The fitness levels were taken between the years of 1971 and 2009, and cases of lung, prostate, and colorectal cancer among the participants was determined from Medicare data from 1999 to 2009. During an average 6.5 year follow-up, 1,310 of the participants were diagnosed with prostate cancer, 200 with lung cancer and 181 men colorectal cancer.

The researchers determined the men who had high CRF in midlife had a 55 percent reduced risk of lung cancer and 44 percent lower risk of colorectal cancer than men with a low CRF; this association was not seen among cases of prostate cancer. The findings also show high CRF was associated with a 32 percent lower risk of cancer death among men who developed lung, colorectal, or prostate cancer around the age of 65.  

"To our knowledge, this is the first study to demonstrate that CRF is predictive of site-specific cancer incidence, as well as risk of death from cancer or CVD following a cancer diagnosis. These findings provide further support for the effectiveness of CRF assessment in preventive health care settings. Future studies are required to determine the absolute level of CRF necessary to prevent site-specific cancer as well as evaluating the long-term effect of cancer diagnosis and mortality in women," the study concluded.

The findings were published in a recent edition of the journal JAMA Oncology.