Inactive lifestyles are responsible for about 200,000 deaths in the US each year, second only to tobacco, which kills about 400,000 (Sallis et al, 2004). People who live in neighborhoods with “traditional” or “walkable” designs report about 30 minutes more walking for transportation each week and more total physical activity, compared to those who live in neighborhoods with less walkable “suburban” designs (Frank et al., 2006). The simple act of walking offers myriad health benefits, including reductions in stress, blood pressure, diabetes, cardiovascular disease, and early mortality, to name a few. An important piece of research called the “busman’s survey", published in The Lancet 60 years ago, found that bus drivers – who sat on their bums all day - had heart attacks at twice the rate of bus conductors, who spent all day on their feet going up and down the stairs of the iconic London double-decker buses. This was the first clue in what is now a large body of literature in the burgeoning area of research called Inactivity Physiology that long hours of sedentary behaviour lead to serious health problems. Despite the benefits and accessibility of walking, the majority of US citizens do not walk continuously for more than 10 minutes at a time in an average week. This data can probably be extrapolated to the majority of Canadians as well. Using data collected from the National Health and Nutrition Examination Survey, researchers examined levels of “active transportation” or “non-motorized transport”, which includes walking and bicycling, as well as body mass index and waist circumference in 9933 subjects. Study participants were over 20 years of age, not pregnant, and had no mobility issues. The researchers learned that 43% of participants did not meet the recommended 150 minutes of physical activity per week. “Overall, 76% of individuals did not walk or bike for more than 10 minutes continuously for transportation in a typical week, and 19% had engaged in no physical activity at all", said the researchers. Active transportation – both high and low amounts – was associated with lower body mass index (BMI), smaller waist circumference, and reduced potential for hypertension. In addition, compared with no active transportation, high active transportation was associated with 31% lower risk of having diabetes. Overall, active transportation was shown to reduce the prevalence of significant cardiovascular risk factors, including obesity and hypertension.
The flip side to minimal active transportation is too much time spent sitting - at a desk, in a car, in front of the computer and tv. Sitting is a death trap! Disturbing statistics on the dangers of sitting include:
- Every hour you sit in front of the television slashes your life expectancy by 22 minutes. Watching television for 6 hours a day takes 5 years off your life.
- Sitting too long can cause non-alcoholic fatty liver disease.
- Sitting more than 6 hours per day increases your risk of death, even if you work out! Female exercises who sit this much are 37% more likely to die over 14 years than those who sit less than 3 hours per day. For male exercisers who sit over 6 hours daily, the risk of death is 18% higher than for those who sit less than 3 hours.
- If you sit more than 3 hours per day, your risk of kidney disease increases.
- Sitting for extended periods raises the risk of developing type 2 diabetes, heart disease, and premature death, even for people who meet the daily physical activity levels recommended by health professionals.
- Prolonged sitting is a risk factor for all-cause mortality, independent of physical activity.
References: Frank, L. et al. (2006). Many Pathways from Land Use to Health. Journal of the American Planning Association, 72(1). Greenland, R and Shilton, T. Redesigning urban environments for active transport. The Guardian, Friday 22 March 2013. Halverson, R. (2013) Active transportation rates dismal. IDEA Fitness Journal, March. Keller, J and Cline, J. (2013) Sitting is a death trap. IDEA Fitness Journal, January. Sallis, J. et al. (2004) Active transportation and physical activity: opportunities for collaboration on transportation and public health research. Transportation Research, Part A 38, pp. 249–268. Exercise Specialist Recommendations:
- Interrupt long periods of sitting with 2 minute breaks of light- or moderate-intensity activity such as walking. This has been shown in recent research to help control blood glucose and insulin levels.
- Bike for transportation.
- Try not to sit for longer than 3 hours a day.
- Walk everywhere you can!