United Kingdom: A new study has suggested that being fit earlier in life can reduce the risk of developing nine different types of cancer in later life by up to 42 percent. While exercise has been previously linked with a lower risk of certain cancers, there has been a lack of comprehensive, long-term studies involving large groups of participants.
The new study, published in the British Journal of Sports Medicine, analyzed data from more than 1 million male Swedish conscripts between 16 and 25, who were followed for an average of 33 years from 1968 to 2005.
The results found that good cardiorespiratory fitness, an individual’s ability to engage in sustained aerobic exercises such as running, cycling, and swimming, was associated with a 42 percent reduced risk of lung cancer, a 40 percent reduced risk of liver cancer, and a 39 percent reduced risk of oesophageal cancer. It was also associated with a lower risk of head and neck, stomach, pancreatic, bowel, and kidney cancer.

Higher cardiorespiratory fitness appeared to be associated with a 7 percent heightened risk of prostate cancer and a 31 percent heightened risk of skin cancer, although it is possible that more frequent prostate cancer screening and sunlight exposure might account for these findings.
The lead researcher, Dr. Aron Onerup, at the University of Gothenburg in Sweden, expressed that he was surprised by some of these broad associations across several organ systems and “by the consistent associations between cardiorespiratory fitness and cancers in the gastrointestinal tract.”
“While cardiorespiratory fitness was associated with half of the cancer sites included, this was less true for muscle strength. So, while we did not look at activities in our study, this might indicate that aerobic activities such as running, biking, sports, and swimming are more likely to be associated with cancer risk than resistance training is,” Mr. Onerup commented.

Reducing cancer risk is not the only reason to exercise. There are compound benefits for emotional health and preventing cardiovascular disease.
Mr. Onerup remarked that “some physical activity is better than none, and more physical activity is better for optimal health outcomes,” and emphasized that “it is never too late to get fit to reap health-protective benefits.”