Over the last couple of years, a slew of new terms have come into popularity to describe how much we move. Physical inactivity, lack of exercise, sedentary behaviour seem to all be used interchangeably to describe people who do not move enough. But here’s the thing…
Physical activity ≠ Exercise
Physical activity refers to movement. Standing, walking, housework, chores – all of those kinds of activities count. Your day-to-day tasks all fall into the realm of physical activity. Exercise on the other hand is different. Exercise is dedicated time spent to movement. Blocked time in your day when you say “I am going to be active doing x”. This constitutes exercise and this is an important component of aging successfully.
So when we refer to sedentary behaviour we are talking about the opposite of physical activity. This is time spent lying down, chilling on the LazyBoy or just plain sitting. It is a low energy state, it’s not really hard to do it. In the research world, we give these tasks a label based on how much work you have to do. They’re called a “metabolic equivalent” or MET. 1.0 METs is sitting, doing nothing. Sedentary behaviour is a fancy term that characterizes how active we are and are activities with a MET score of less than 1.5 .
We can measure this a couple of ways. We have the information people tell us (subjective) or what we are able to measure (objective). An example of subjective questions are “how much time do you spend sitting?” . This can give you an idea of the amount of time but often we SERIOUSLY underestimate how much time we spend watching TV or roaming the internet (or perhaps we just don’t want to admit we binge watched 8 hours of Netflix!). For this reason, sometimes those questions are specifically asked instead. Objective units, on the other hand, are when we place a tracking device on a person that measures their activity levels. These are more accurate representations of what a person does day-to-day.
This month in the Journal of Aging and Physical Activity, Harvey and colleagues did a systematic review (the gold standard of research) looking at the amount of time older adults (over 60) spend being sedentary (1). They looked at studies from all over the world from Canada to Australia. What they found was that across the board, older adults spend more time sitting than younger adults. Across countries there actually wasn’t a huge range of variability – the results were the same.
So what did they find?
Harvey and colleagues found that when you asked older adults how much time they spent sitting, they told you a number between 5.2 to 6.7, with an average of 5.3 . When they stuck a machine on them that really measured it, the numbers looked a little different…
Older adults spent 8.5 – 10.7 hours sitting! That is a HUGE percentage of their day!
The reason why this is so important is that sedentary behaviour has been linked to an increase in all-cause mortality (passing away from any cause), obesity, cardiovascular disease and a variety of cancers. If you report sitting more than 3 hours a day, it can reduce your life expectancy by 2 years. The worrying part of these statistics is that although exercise can blunt some of the negative consequences of sitting, it does not completely take it away. These risks exist irrespective of whether you participate in an exercise program.
The Take Aways
– We need to work on continue to be up and active as we get older
– Exercising is a large component of staying healthy as we age but that does NOT mean we can spend the rest of our time being a couch potato.
1. Harvey JA, Chastin SFM, Skelton DA. How sedentary are older people? a systematic review of the amount of sedentary behavior. J Aging and Phys Act. 2015. 23: 471-87.