We featured all the ways that a desk job can impact your posture and what you can do to fix your work-space in a previous blog but there are many definitions of a “sedentary” lifestyle. It generally refers to either being not physically active or spending the vast majority of time in a low energy expenditure state such as sitting.  The concern of too much sitting time is a great one given that our most common activities are all done in this position: working at a desk, watching television, driving a car and eating, to name a few.

How Common is a Sedentary Lifestyle? 

• Children and adults in North America spend between 55-70% of their waking hours sedentary, translating into nine to 11 hours of sitting per day
•  70% of 13-year-olds watch more than two hours of TV per day. The Canadian Pediatric Society and American Academy of Pediatrics recommend that children and youth spend no more than two hours per day in front of screens

This is all important information because these levels of sedentary activity can severely impact your health in a negative way. Here are some reasons why you should strongly consider incorporating movement into your daily regimen!

General Risk:

The Harvard Alumni Study concluded that sedentary men have a 31% higher risk of death than more active men.

Bone Health

Reductions in bone mineral density of 1-4% in the lumbar spine, femur and hip of healthy men and women have been reported following 12 weeks of bed rest.

Heart Health

Researchers have found a 20-30% reduction in peripheral vascular function with a significant rise in blood pressure after only five days of bed-rest. Other studies have found significant increases in total cholesterol, triglycerides, glucose, and insulin resistance (up to 67% greater insulin response) after only five days as well. A decrease in the “good” HDL cholesterol levels after 20 days of bed rest has also been noted.

Independent of physical activity time, the odds of having metabolic syndrome are three times higher in those with at least five hours per day of screen time compared with those with one hour or less. TV viewing time has also been linked to hypertension in obese children, where those who watched TV four hours per day had 3.3 times the risk of hypertension compared with those who watched less than two hours per day.

Cognitive Function

The odds of developing dementia have been found to be twice as high in those with sedentary behavior when compared to those that are physically active.

Obesity

TV watching and video game use have been found to be independent risk factors for children being overweight or obese. Children watching three to five hours of TV per day have been shown to have up to a 44% increased risk of being overweight and as high as a 61% increased risk for being obese. In a study of more than 50,000 non-obese women, each two hour per day increase in TV viewing time was associated with a 23% increase in obesity and each two hour per day increase in sitting at work was associated with a 5% increased risk of obesity.

Diabetes

Various research has found that each two hour per day increase in TV viewing time increased the risk of developing type II diabetes by 14-20%, independently of physical activity amounts. Each two hour per day increase in sitting at work was associated with a 7% increase in diabetes risk.

Cancer

A large prospective cohort study of almost 500,000 men and women aged 50-71 years found that high levels of TV and video watching were associated with an increased risk of colon cancer in both men and women. In addition, women that spent more than seven hours per day sitting had an increased risk of endometrial cancer compared with those who were sitting less than three hours per day.

Quality of Life

Children that are more physically active report greater body satisfaction and self-esteem.  Even without a change in body weight or size, greater physical activity and exercise improves overall self-esteem in youth. Both physical and mental quality of life measures have been shown to increase in a dose-dependent manner with more exercise in healthy adults as well.

Mood

A clear relationship has been found between sedentary activity and the risk of developing a mental disorder, with a 31% higher risk of mental disorder found in those with the highest amounts of sedentary activity compared with less sedentary people. One study found that women accumulating 7,500 steps per day or more had a 50% lower prevalence of depression when compared with women accumulating less than 5,000 steps per day.

Sleep

The odds of having sleep disturbances are 38% higher in those with sedentary lifestyles versus those with more active lifestyles. Now that you know the impacts that a sedentary lifestyle can have on your health, here are some suggestions on how to avoid it:

What Are Some Simple Ways to Reduce your Sedentary Activity?    

• Park further away from your destination so that you can walk a short distance
• Choose walking or biking over driving when time and circumstances permit
• Choose the stairs instead of the elevator or escalator
• If applicable, speak with your employer about implementing a sit-stand desk that can easily adjust between the two positions
• Take a brisk walk on your lunch time
• Stand while talking on the phone
• Walk to your colleagues’ office instead of sending an email
• Reduce TV time in the evening and opt for a family-oriented or social activity that involves physical activity (such as hiking, golfing or swimming)
• Set a timer on your phone or watch to remind you to stand every hour

References:

Ryan S Falck, Jennifer C Davis and Teresa Liu-Ambrose. What is the association between sedentary behaviour and cognitive function? A systematic

Review. Br J Sports Med 2016;0:1–12.

Tremblay MS, Colley RC, Saunders TJ, Healy GN and Owen N. Physiological and Health Implications of a Sedentary Lifestyle. Appl Physiol Nutr Metab 35: 725–740 (2010)

Yang Y, Shin C, Li D and An R.  Sedentary Behavior and Sleep Problems: a Systematic Review and Meta-Analysis. Int J Behav Med 2016; 1-12

Chau JY, Grunseit AC, Chey T, et al. Daily Sitting Time and All-Cause Mortality: A Meta-Analysis. Gorlova OY, ed. PLoS ONE. 2013;8(11):e80000. doi:10.1371/journal.pone.0080000.