According to the lead author of the study, Susan Lakoski, MD, assistant professor of medicine at the University of Vermont:
"While poor fitness is already known to predict future cardiovascular disease, this is the first study to explore fitness as a marker of future cancer risk prognosis.
This finding makes it clear that patients should be advised that they need to achieve a certain fitness level, and not just be told that they need to exercise. And unlike exercise behavior, which relies on patient self-reporting, fitness can be objectively and accurately measured in a clinical setting."
A total of 17,049 men participated in the study. They each received a cardiovascular fitness assessment from the Cooper Institute at a median age of 50. The test involved walking on a treadmill with a variation of different speeds and elevations. They recorded the men's performance with the ratio of metabolic rate (the rate of energy consumption), known as metabolic equivalents or METs.
The team divided the participants into different groups based on their level of fitness. The researchers then analyzed their medical histories to determine whether they had developed either lung, colorectal, or prostate cancer.
In this study, men who were in their 40s who achieved 13.5 minutes in the fitness test belonged to the lowest quintile for fitness as well as men in their 50s who achieved less than 11 minutes.
During the follow-up period of 20 to 25 years, a total of 2,332 men were diagnosed with prostate cancer, 277 were diagnosed with lung cancer and 276 were diagnosed with colorectal cancer.
They adjusted the results of the study for factors such as BMI, smoking habits and age.
The risk of lung or colorectal cancer decreased by 68 and 38 percent among men who were the most physically fit and active compared to those who were not active at all.
The researchers found that physical activity did not have any effect on the rate of prostate cancer diagnosis.
Although it's been shown that exercise can reduce the risk of dying from prostate cancer. Previous research has indicated that men with prostate cancer who exercise vigorously have a notably reduced risk of dying from the disease compared to other diagnosed men.
Men who were physically fit at the time they developed cancer had a much higher survival rate and lower risk of dying from the cancers compared to men who were not fit. In fact, a 1MET increase in fitness was associated with a 14 percent reduced risk of dying from the cancer, as well as a 23 percent reduced risk of dying from cardiovascular disease.
In addition, the researchers noted that patients who weren't fit yet not obese were still at an increased risk of cardiovascular disease (CVD), suggesting that people should be aware that fitness also impacts risk.
Exercise has been shown to have huge beneficial effects on people diagnosed with cancer and it's also been found to help minimize the risk recurrence, or another cancer developing.
ASCO President Sandra M. Swain, said:"This important study establishes cardiorespiratory fitness as an independent and strong predictor of cancer risk and prognosis in men. While more research is needed to determine if similar trends are alid in relation to other cancers and among women, these results indicate that people can reduce their risk of cancer with relatively small lifestyle changes."