A Conversation with Dr. Richard Troiano
Dr. Richard Troiano 1 is an epidemiologist in the Risk Factor Monitoring and Methods Branch 2 of NCI’s Division of Cancer Control and Population Sciences 3 (DCCPS). In 2006, he was detailed to the U.S. Department of Health and Human Services (HHS) Office of Disease Prevention and Health Promotion to help develop the first-ever federal Physical Activity Guidelines for Americans 4, which were released last fall.
Dr. Richard Troiano
What are the goals of the Guidelines?
The Physical Activity Guidelines are designed to provide information and guidance on the types and amounts of physical activity that provide substantial health benefits for Americans aged 6 years and older. The main idea behind the Guidelines is that regular physical activity can produce long-term health benefits.
Being physically active is one of the most important steps Americans can take to improve their health. The Guidelines note that some activity is better than none, and more activity is even better. Both aerobic and muscle-strengthening activities are beneficial. Many health benefits occur with at least 2 hours and 30 minutes of moderate-intensity physical activity per week or the equivalent 1 hour and 15 minutes of vigorous-intensity activity. Aerobic activity should be performed in episodes of at least 10 minutes, and preferably spread throughout the week. To gain additional and more extensive health benefits, adults can increase their aerobic physical activity to 5 hours a week of moderate-intensity or 2 hours and 30 minutes a week of vigorous-intensity aerobic physical activity or an equivalent combination of moderate- and vigorous-intensity activity. Adults should do muscle-strengthening activities on at least 2 days a week.
What are their implications for cancer control?
The HHS Physical Activity Guidelines Advisory Committee examined both cancer prevention and benefits for cancer survivors as outcomes related to physical activity. Physical activity was clearly shown to reduce the risk of cancers of the colon 5 and breast 6, and it may also reduce the risk of cancers of the endometrium 7 and lung 8.
It appears that a relatively large amount of physical activity is required to see a reduction in cancer risk—about 3.5 to 7 hours per week. This is toward the upper end of the recommended range for health benefits in the Guidelines. However, cancer survivors seem to have noticeably improved fitness and quality of life even with amounts of physical activity at the low end of the recommended range. Just getting a 30-minute walk three times a week may provide benefits.
What is NCI’s research agenda for examining the link between physical activity and reduced cancer risk?
NCI supports a broad variety of research related to physical activity and cancer. One example is the Health, Eating, Activity, and Lifestyle (HEAL) Study 9 that examines relationships among physical activity, biomarkers, and breast cancer prognostic factors, as well as intermediate outcomes and recurrence in women with early stage breast cancer.
NCI is also stimulating novel research in the assessment of physical activity. Through the Improving Diet and Physical Activity Assessment 10 Program Announcements and the Exposure Biology Program 11 of the Genes, Environment and Health Initiative, grants have been awarded to develop and validate new objective measures of physical activity that use motion sensors, heart rate monitors, and geographic location sensors. These devices will enhance our understanding of the relationship between physical activity and health.
