Maintaining fitness during early adulthood has been revealed to correlate with a significantly diminished risk—up to 42 per cent in some instances—of developing nine distinct forms of cancer in one’s later years, as indicated by an extensive, long-term investigation.
Although the connection between exercise and a decreased likelihood of certain cancers has been established previously, comprehensive and large-scale studies encompassing numerous cancer types have been limited.
This recent study, featured in the British Journal of Sports Medicine, harnessed data sourced from over one million male Swedish conscripts aged 16 to 25. These participants were monitored over an average span of 33 years, spanning from 1968 to 2005. The findings unveiled that robust cardiorespiratory fitness—referring to an individual’s capacity to engage in sustained aerobic activities such as running, cycling, and swimming—was linked to a 42 per cent reduction in the risk of lung cancer, a 40 per cent decrease in the risk of liver cancer, and a 39 per cent drop in the risk of oesophageal cancer.
Moreover, this higher level of cardiorespiratory fitness appeared to be associated with lowered risks of head and neck, stomach, pancreatic, bowel, and kidney cancers. Interestingly, a higher cardiorespiratory fitness level appeared to carry a 7 per cent heightened risk of prostate cancer and a 31 per cent increased risk of skin cancer. However, these findings might be influenced by more frequent prostate cancer screenings and increased sunlight exposure.
Dr. Aron Onerup, the lead researcher at the University of Gothenburg in Sweden expressed his surprise at the broad associations observed across various organ systems and the consistent connections between cardiorespiratory fitness and gastrointestinal cancers. In regard to the unexpected rise in prostate and skin cancer risks, Onerup stated that subsequent research had indicated that men with heightened fitness levels were more prone to receiving diagnoses of non-fatal prostate cancers.
Nonetheless, this study does not fully account for the impact of dietary habits, alcohol consumption, and smoking, all of which are more likely to influence the likelihood of cancer development, according to Dr. Claire Knight, senior health information manager at Cancer Research UK.
On the whole, the results present a compelling argument and strengthen the rationale for promoting interventions aimed at augmenting cardiorespiratory fitness among young individuals throughout their school and university years, asserted Dr. Mark Hamer, a professor of sport and exercise medicine at University College London. While some other researchers cautioned against drawing causal conclusions from observational studies of this nature, Hamer added, “The extended follow-up period effectively eliminates concerns of reverse causation, a challenge that many previous studies have encountered in their analyses.”
Onerup noted, “While cardiorespiratory fitness displayed associations with half of the cancer types examined, this correlation was less pronounced for muscle strength. Thus, even though our study did not delve into specific activities, it may suggest that aerobic pursuits like running, cycling, sports, and swimming carry a stronger likelihood of cancer risk reduction than resistance training.”
However, mitigating cancer risk is not the only incentive for engaging in regular physical activity. The advantages extend to emotional well-being and the prevention of cardiovascular diseases. Onerup affirmed that “any level of physical activity is superior to none, and greater physical activity yields enhanced health outcomes.” He emphasised that it is never too late to pursue fitness to reap the protective benefits for one’s health.
Regarding the optimal exercise duration, Knight recommended 150 minutes per week, while highlighting the flexibility to gradually increase activity over time. She assured that various options exist to enhance activity levels, whether it involves brisk walks, cycling with companions, or even completing household chores—all of these contribute to being more physically active.