Studies have shown that smoking just one cigarette reduces your life by eleven minutes1. Probably not surprising but what if I told you that the seemingly harmless pastime of watching TV also reduces your life expectancy—surprised? Researchers from Australia have estimated that every hour of television watched after the age of 25 is associated with a twenty-two minute reduction in average life expectancy2. Based on their calculations, an adult who spends an average of six hours per day watching TV can expect to live 4.8 years fewer than someone who does not watch TV. Sedentary behavior has long been associated with higher risk of death, however this study shows television watching specifically is associated with a loss of life similar to other major risk factors such as lack of physical activity and obesity.
The act of sitting has been emerging as a major risk to our health and is unfortunately something we are doing more and more of. We discussed research related to this in one of our blogs in February of last year. The study highlighted showed that meeting the physical activity requirements (150 minutes of moderate intensity activity a week) wasn’t enough to decrease the risk of heart disease associated with prolonged periods of sitting3. At the American Institute for Cancer Research’s (AICR) Annual Research Conference on Food, Nutrition, and Physical Activity that was held in Washington this month, researchers presented more evidence of the protective link between physical activity and various forms of cancer–not surprisingly4. However, also presented was emerging data that indicates that sitting time is a strong candidate for being a cancer risk factor on its own—again, independent of how much exercise people do just as in heart disease. What this research is suggesting is that while physical activity is important, on its own it may not be enough. We have to make an effort to protect ourselves from various diseases, cancer included, by infusing our day with periods of activity.
So how can we do this if so much of our day is “sitting-based”? The AICR is urging Americans to break every hour for 2 minutes of activity. Here are some suggestions on how to do that:
• Set a timer to remind you to get up every hour and walk down the hall.
• Walk during phone calls.
• Go talk to a colleague instead of typing an email.
• Take the stairs.
• Keep small exercise equipment at your desk like light dumbbells or exercise bands.
• Find active modes of transportation if possible i.e. walk to the bus stop, ride your bike.
• Keep television time to a minimum or find ways to be active during your favorite show.
• And of course don’t forget to accumulate 150 minutes of moderate intensity physical activity throughout the week.
The AICR calls this “Make Time” (moderate/ vigorous physical activity) + “Break Time” (activity breaks throughout the day) = Cancer Protection. As you can see from their picture below, what we do in our day really has a tremendous impact on our level of risk. Notice how even though the first three individuals pictured have the same level of “make time” (activity in green), they do not have the same cancer risk. The person with the least amount of “break time” (activity in yellow) has a higher risk for cancer because that meant that they spent more of their day being sedentary (in gray). And as noted earlier, research has shown that this concept holds true for heart disease as well.
So the take-home-message:
We have some control over our risk of developing disease—we are in the driver’s seat of our health! So make time for activity, even small bits, and reduce the amount of time that you are sedentary. Doing so just may save your life!
1. Shaw , M., Mitchell, R., Dorling, D. (2000). Tiem for a smoke? One cigarette reduces your life by 11 minutes. Brit Med J, 320 (7226): 53.
2. Veerman, J.L., Healy, G.N., Cobiac, L.J., Vos, T., Winkler, E.A., Owen, N., Dunstan, D.W. (2011) Television viewing time and reduce life expectancy: a life table analysis. Br J Sports Med, doi: 10.1136/bjsm.2011.085662.
3. Katzmarzyk, P.T., Church, T.S., Craig, C.L., & Bouchard, C. (2009). Sitting time and Mortality from All Causes, Cardiovascular Disease, and Cancer. MSSE, 41(5),998-1005
4. American Insittue for Cancer Research. (2011). New research: getting up from your desk can put the “breaks” on cancer. Experts urge americans to rethink outdated notions of physical activity [Press Release]. Retrieved from: http://www.aicr.org/press/press-releases/getting-up-from-your-desk.html