Sitting Probably Isn't Killing You

By Aadam | December 3, 2019

The internet is reaming with claims that sitting is killing you. But how much truth is there to this claim? Turns out not much.

Every now and then as I’m scrolling through the interwebz I’ll see an article that reads: “BAD NEWS: SITTING IS KILLING YOU!” Or my personal favourite, “SITTING IS THE NEW SMOKING!”

And then everyone freaks the fuck out and decides that going forward WE SHALL SIT NO MORE—STANDING IS OUR LIFE NOW.

But before you forego sitting and drop some serious cash on a shiny new standing desk–you probably want to read this. And by probably, I mean definitely.

Let’s get this out of the way first: standing doesn’t burn that many more calories than sitting

In one study, 74 healthy subjects were fitted with masks that measured oxygen consumption, allowing the researchers to calculate how many calories they burned. 1

Oxygen-Mask-Sitting-Standing-Energy-Expenditure

They then engaged in a number of activities lasting 15 minutes each:

  • Sitting using a laptop
  • Sitting watching TV
  • Standing watching TV
  • Walking at a self-selected pace (<3 mph)

A recent meta-analysis looked at 46 studies with 1184 participants and found the mean difference in energy expenditure between sitting and standing was 0.15kcal/min. 2 Researchers commenting, ‘By substituting sitting with standing for 6 hours/day, a 65 kg person will expend an additional 54 kcal/day.’

And Beers et al. investigated the energy expenditure between sitting on a therapy ball, sitting in a chair, or standing while typing and found the exercise ball and standing conditions only burned 4.1kcal more than the sitting condition. 3

beers-energy-expenditure-graph
Adapted from Beers et al., 2008

As you can see, the difference in calories expended between sitting and standing isn’t as substantial as some claim.

Further, just like NEAT, there are individual differences in how many calories one burns when standing. Some people don’t really increase their energy expenditure despite standing, while others can see a significant increase. Aa

Standing isn’t entirely innocuous either

Going from sitting all day to standing all day can present its own set of problems like swelling in the lower limbs and leg, foot, and back pain. 4

And despite the numerous ‘sitting is killing you’ claims, it’s not sitting that’s the problem but a lack of movement overall.

Pulsford et al., (2015) tracked the health of 5,132 people over 16 years…

And found sitting was only associated with mortality risk in those who reported zero minutes of weekly walking or moderate-to-vigorous physical activity.

A 2016 study analysed data from more than 1 million people and found that 60 to 75 minutes of moderately intense physical activity per day countered the effects of too much sitting. 5

A note on epidemiological studies

All the studies on this type of topic (i.e., ‘sitting is killing you’) are epidemiological. These studies can’t prove causation–so, in this case, the studies can’t prove that sitting is actually killing you or leading to poor health–they can only show a correlation and other factors can be involved.

For example, all the studies (if not the majority) showing increased sitting time is associated with increased all-cause mortality have been based on TV viewing time. The problem with using TV viewing time is there could be other factors involved.

One of these factors is calorie intake.

What do people generally do while watching TV? They eat snacks. And if people are sedentary and eating more calories than they require, this can lead to fat gain which can result in poor health outcomes. But if the researchers don’t factor in these other variables, you’re left with some clickbait Buzzfeed article like ‘SITTING IS BASICALLY SMOKING AND YOU’RE GONNA DIE, FUCKFACE!’

So it’s not sitting in and of itself that’s the problem, though that can be one factor, but a combination of sitting (sedentary lifestyle) and chronic overeating.

This is why when physical activity is factored in, the mortality risk decreases. We know physical activity has a number of health benefits, and people who are physically active also tend to have healthier habits overall. And it’s the combination of several factors that can either increase or decrease mortality risk.

With all of that said, you probably should avoid sitting on your ass all day

Breaking up sitting time with bouts of activity has a number of health benefits.

Even when calorie intake was reduced to match energy expenditure, there was still an 18% reduction in insulin sensitivity.

Conversely, breaking up sitting time with movement–even for short periods of time–has shown to improve the body’s ability to handle insulin.

dunstant-et-al-2012-sitting

In another study, office workers who used a sit-stand station after eating a lunch buffet saw a 43% lower blood glucose response compared to workers who remained seated.

sitting-standing-glucose-response-01

Furthermore, when sedentary office workers replaced sitting with sitting and standing they reported an increased sense of well-being, energy, decreased fatigue, reduced appetite and food intake. 6

Taking all of this together, if you have a job that requires you to sit for long periods of time–IT’S TOTALLY FINE. You’ll be ok. Your heart will not randomly implode because you were sitting down.

Just ensure you’re getting up every 30-40 mins to move, walk, stretch, etc. Alongside this, partake in regular physical activity 3-4x per week (like strength training) and you’ll be ok.

Remember that ‘poor health’ (or mortality risk) doesn’t happen in a vacuum. Nail the big rocks like regular exercise, good nutrition, daily activity and don’t stress about the little things.