Too much sitting is killing us!

Introduction

Both the American Heart Association and American College of Sports Medicine have exercise guidelines that most masters athletes meet – 30 minutes of moderate intensity exercise 5 days per week or vigorous exercise 3 times per week. Doing this lowers the risk of both morbidity (illness and disease) and mortality (death). However, even in older athletes like ourselves, approximately 55% of our day is spent sitting (eg driving, working at a desk, eating meals,watching TV). This study examined sitting time, disease status and mortality in a large group of Canadians to see what the relationship was between sitting time, disease and death.

The Research

A sample of 17,013 male and female Canadians 18-90 years were studied as part of the Canada Fitness Survey. Evaluation of daily sitting time (five categories – almost none of the time, one fourth of the time, half of the time, three fourths of the time, almost all of the time), leisure time physical activity, smoking status, and alcohol consumption was conducted at baseline. Participants were followed for an average of 12 years to determine disease status and death rates.

The Results

There were 1832 deaths (759 of cardiovascular disease (CVD) and 547 of cancer) during the 12 years of follow-up. There was a progressively higher risk of mortality across higher levels of sitting time from all causes and CVD but not cancer. Similar results were obtained when analysis was done to compare by sex, age, smoking status, and body mass index. Age-adjusted mortality rates per 10,000 person years of follow-up were 87, 86, 105, 130, and 161 in physically inactive participants but, as we’d expect (lower) 75, 69, 76, 98, 105 in active participants across all sitting time categories.

So What?

The researchers concluded that the higher the amount of sitting time the greater the risk of death from all causes and CVD in particular, independent of leisure time physical activity. In addition to the promotion of moderate-to-vigorous physical activity and a healthy weight, we all should stop sitting for extended periods. While no guidelines currently exist as to how much sitting we should do, Exercise and Sport Science Australia suggest the following:

  1. Interrupt sitting time every 30 minutes for 2 minutes or at least every hour for 2-4 minutes.
  2. Introduce standing or walking meetings. Yep, have a short meeting with a colleague(s) by going for a walk
  3. Get a telephone headset or extra-long phone cord so you can stand during phone calls.

Australia’s Heart Foundation (see page 3) have some tips that might give you some ideas. Another respected source, The Mayo Clinic in the USA has some tips too. Check them out!

Source: Katzmaryzyk, P. and others (2009). Sitting time and mortality from all causes, cardiovascular disease, and cancer. Medicine and Science in Sports and Exercise, 41(5): 998-1005.