Not that you need anything else to worry about, but now experts are claiming that sitting can kill you. We all know the dangers of a sedentary lifestyle, but this latest news is more alarming for those of us who consider ourselves active because we work out (that is, do planned exercise) most days. In a series of recent studies on sedentary behavior conducted at the Pennington Biomedical Research Center in Baton Rouge, LA, and elsewhere, researchers have found that sitting for prolonged periods — regardless of whether you also exercise regularly or where and when the sitting takes place — could be bad for your health and your longevity.
By way of example, one study followed a group of Canadian adults for 12 years and found a dose-response association between sitting time and mortality from all causes and cardiovascular disease, independent of leisure time physical activity1. In addition to the promotion of moderate-to-vigorous physical activity and a healthy weight, it appears we should all also discourage sitting for extended periods since it is the overall hours of sitting that matters most, particularly when they’re consecutive.
What determines whether each person is active or sedentary? Is there something in our genetic makeup that drives us to move more, or less, all day long? Researchers have also tried to find the answer to those questions. A study undertaken by Novak and colleagues at the Mayo Clinic2 attempted to determine if lean individuals naturally expend more energy doing movement each day. The answer? It appears that people with higher VO2max values (i.e., a higher maximal aerobic capacity) naturally spend more time being active throughout the day. Hence, aerobic capacity may be the trait that underlies both physical activity levels and leanness, and it has already been well established that having a low aerobic fitness level increases mortality, particularly in individuals with chronic conditions like diabetes. Generally, activity begets more activity because the better you feel while being active, the more likely you are to keep moving.
If moving around feels hard to you because your aerobic capacity is so low, then you’re more likely to keep sitting and avoid any unnecessary movement.
Based on these and other related findings, exercise experts are beginning to suggest that we rethink how we define physical activity to highlight the dangers of prolonged sitting. Up to this point, official guidelines have focused on planned activity, not trying to limit how much time people spend in a seated position.
If you are one of those people who exercise every day — but still spend a lot of time sitting — you may benefit more by spreading that exercise across the day, rather than doing it all at once. That works for diabetes management as well if you can prevent and manage post-meal glucose spikes with muscular activity at various times during the day. You can also simply break up the time you spend sitting with frequent breaks of standing, walking, fidgeting, and other physical movement. So, what are you waiting for? Stop reading this article and get up and do something, anything!
- Katzmarzyk PT, Church TS, Craig CL, Bouchard C. Sitting time and mortality from all causes, cardiovascular disease, and cancer. Med Sci Sports Exerc. 41(5):998-1005, 2009.
- Novak CM, Escande C, Gerber SM, Chini EN, Zhang M, Britton SL, Koch LG, Levine JA. Endurance capacity, not body size, determines physical activity levels: role of skeletal muscle PEPCK. PLoS One. 4(6):e5869, 2009.
To sign up for 5 free healthy living reports via e-mail, visit www.lifelongexercise.com. For more information on exercise and physical activity in general, also check out my web site at www.shericolberg.com. If you need tips for getting started on an exercise/lifestyle program, consult The 7 Step Diabetes Fitness Plan. People with any type of diabetes who are already more active may benefit from reading the Diabetic Athlete’s Handbook.
Copyright © Diabetes In Control, Inc., www.DiabetesInControl.com, 2010