Are we getting enough physical activity?
Federal guidelines recommend that adults perform at least 150 minutes/week of moderate-to-vigorous intensity physical activity or 75 minutes/week of vigorous-intensity physical activity (or some equivalent combination of the two), and that this activity should be performed in spurts of 10 minutes or more. Yet when measured objectively (using electronic accelerometers rather than by self-report), less than 5 percent of adults are getting sufficient physical activity in accordance with these guidelines. The high prevalence of physical inactivity in the U.S., particularly among older Americans, is partially responsible for our high rates of obesity, cardiovascular disease, Type 2 diabetes, and cancer.
Why is physical activity relevant to cancer?
Physical activity is associated with a reduced risk of several cancers, including breast, prostate, and colorectal cancers. Similarly, physical activity is associated with significantly better survival from these tumors. For example, breast cancer survivors who are highly active have a 10-35% lower risk of mortality than those who are inactive. The mechanisms underlying the link between physical activity and cancer include adiposity, hormones, blood sugar regulation (insulin and associated factors), inflammatory factors, as well as new pathways currently under exploration. Breast, prostate, and colorectal cancer are among the most common cancer types, with a combined incidence of 600,000 new cases per year in the US. Annual mortality from these cancers is 94,000 per year. As cancer screening and treatment continues to improve, 5-year survival rates are increasing, creating a large population of cancer survivors. There are now 7.3 million Americans who have had a diagnosis of breast, prostate, or colorectal cancer. In addition to the benefits of physical activity on cancer survival itself, an active lifestyle can also help reduce the risk of some of the common late effects of cancer treatment, including heart disease, osteoporosis, and fatigue.
With this in mind, our research addresses the following broad questions:
- What is the association between physical activity and cancer risk and survival?
- How can we leverage technology to promote physical activity among cancer survivors and at-risk populations?
- How can we improve our measurements and assessment of physical activity?
- What is the relationship of excessive sedentary behavior (sitting) to cancer risk and prognosis, and how might we help cancer survivors reduce their sitting time?
- How can we better integrate physical activity promotion with clinical care for cancer survivors?