Exercise has broad and significant health benefits, making it among the most important healthy behaviors you can adopt. These benefits include improved muscular strength and endurance, stronger bones, and better cardiovascular system function. Exercise is also essential for maintaining a healthier body weight and body composition and improving metabolic health through blood glucose and lipid regulation.
But exercise causes changes at the cellular and hormonal levels that have even broader effects. Among these is a reduction in inflammation, which has long been linked to a lower risk of heart attack. Accumulating research suggests that reduced inflammation and improved immune system function may be an important way in which exercise reduces the risk of cancer. The role of exercise in cancer prevention and treatment is the topic of my Health & Fitness column in the Aiken Standard this week.
While we typically associate the immune system with communicable diseases like cold or flu (and now COVID), our immune system plays an important role in the body’s defense against cancer. Conditions like obesity, poor nutrition, and a sedentary lifestyle can promote chronic inflammation. Among other negative effects, inflammation can interfere with the normal functioning of the immune system. This impairs your cells’ natural cancer-fighting capacity, making it more likely that cancer will develop and spread. Exercise can reverse the immune system damage caused by chronic inflammation, reducing the risk of cancer development and progression as well as making it less likely you will become sick from a cold or flu.
The idea that exercise can reduce the risk of cancer isn’t new. I have written previously about the fact that regular physical activity can lower breast cancer risk by as much as 30%, improve survival, and reduce the risk of recurrence. One study confirms that high levels of physical activity can significantly lower the risk of breast cancer along with many other common types including colon, bladder, lung, kidney, and endometrial cancers.
In addition to helping reduce the risk of cancer development and recurrence, regular exercise can help you handle cancer treatment better. To be sure, cancer treatment can lead to extreme physical consequences including losses in weight, muscle mass, strength, and endurance. At least some of this is due to more time resting and less time being active, the effects of which occur within days and get worse over time.
You may have noticed this as weakness and fatigue after spending a few days in bed with the flu. Muscle strength declines at a rate of over 1% per day of bed rest, and can be 50% lower following as little as three weeks. That reduction in strength could limit a person who was already deconditioned to a point where he or she would have difficulty completing the most basic activities of daily living. Bed rest can also reduce bone density, exposing patients to a greater risk of fracture.
The fitter you are when you begin treatment, the fitter you will be at the end because you have “saved” more strength and endurance in your fitness bank. You simply have more you can lose before you get to a point at which you can’t complete your normal activities. In fact, maintaining physical activity is a key component of cancer treatment. And post-cancer exercise programs are becoming more common as a way to help women recover from cancer treatment and rebuild strength, endurance, and feelings of wellbeing.
The best approach is to be active now to reduce your risk of cancer (and many other chronic diseases) and build strong muscles and bones to help you successfully handle any cancer treatment or periods of other illness you may encounter later.