Skip to main content
The Globe and Mail
Support Quality Journalism.
The Globe and Mail
First Access to Latest
Investment News
Collection of curated
e-books and guides
Inform your decisions via
Globe Investor Tools
Just$1.99
per week
for first 24 weeks

Enjoy unlimited digital access
Cancel Anytime
Enjoy Unlimited Digital Access
Get full access to globeandmail.com
Just $1.99per week for the first 24weeks
Just $1.99per week for the first 24weeks
var select={root:".js-sub-pencil",control:".js-sub-pencil-control",open:"o-sub-pencil--open",closed:"o-sub-pencil--closed"},dom={},allowExpand=!0;function pencilInit(o){var e=arguments.length>1&&void 0!==arguments[1]&&arguments[1];select.root=o,dom.root=document.querySelector(select.root),dom.root&&(dom.control=document.querySelector(select.control),dom.control.addEventListener("click",onToggleClicked),setPanelState(e),window.addEventListener("scroll",onWindowScroll),dom.root.removeAttribute("hidden"))}function isPanelOpen(){return dom.root.classList.contains(select.open)}function setPanelState(o){dom.root.classList[o?"add":"remove"](select.open),dom.root.classList[o?"remove":"add"](select.closed),dom.control.setAttribute("aria-expanded",o)}function onToggleClicked(){var l=!isPanelOpen();setPanelState(l)}function onWindowScroll(){window.requestAnimationFrame(function() {var l=isPanelOpen(),n=0===(document.body.scrollTop||document.documentElement.scrollTop);n||l||!allowExpand?n&&l&&(allowExpand=!0,setPanelState(!1)):(allowExpand=!1,setPanelState(!0))});}pencilInit(".js-sub-pencil",!1); // via darwin-bg var slideIndex = 0; carousel(); function carousel() { var i; var x = document.getElementsByClassName("subs_valueprop"); for (i = 0; i < x.length; i++) { x[i].style.display = "none"; } slideIndex++; if (slideIndex> x.length) { slideIndex = 1; } x[slideIndex - 1].style.display = "block"; setTimeout(carousel, 2500); } //

The question

Can sitting too long really hurt my health - even if I exercise regularly?

The answer

Story continues below advertisement

The numerous studies linking excessive time in front of TV and computer screens with such health problems as heart disease and diabetes may sound like they belong in the Journal of Really Obvious Research. After all, you're not getting any exercise when you're lying on the couch eating chips.

But there's a subtle point whose implications are only now being appreciated: sitting (or lying down) too much is not the same as exercising too little.

Two new studies highlight the growing consensus that long bouts of uninterrupted sedentary behaviour carry health risks that can't be erased even if you're getting plenty of exercise at other times during the day. Researchers are now rushing to determine exactly what counts as "sedentary," and how people whose jobs require them to sit at a desk for the majority of their waking hours can mitigate some of these risks.

In a study reported in January in the Journal of the American College of Cardiology, British researchers monitored 4,512 adults for 4.3 years, and found that those who accumulated more than four hours of screen time daily were twice as likely to be hospitalized or die from a "major cardiac event" compared with those who got two hours or less.

Crucially, this relationship held true no matter how much exercise the subjects got, which suggests that the problem with too much screen time isn't simply that you don't burn as many calories as you consume. Instead, studies with rats and mice show that any muscle that doesn't contract for several hours starts to undergo harmful metabolic changes.

Over the past decade, scientists have observed that levels of an enzyme called lipoprotein lipase drop in muscles left idle for too long. This enzyme is responsible for drawing fat from the bloodstream into muscles, where it's burned as fuel. When the muscles don't need any fuel, the fat remains in the bloodstream and wreaks havoc elsewhere in the body.

"The animal research and the few physiological studies that have been done suggest that as long as a muscle is contracting, regardless of how low the intensity is, that seems to prevent you from experiencing some of the metabolic adaptations that happen when you're sedentary," says Travis Saunders, a researcher at the Children's Hospital of Eastern Ontario in Ottawa who co-authored a recent review paper on this emerging field of study.

Story continues below advertisement

That means that household chores and simple tasks such as walking to a bathroom on another floor are enough to qualify as non-sedentary. Whether simply standing up counts - and if so, for how long - will only be settled by further research. "It's a grey zone," Mr. Saunders says.

There's more encouraging news for committed desk jockeys in a forthcoming study in the European Heart Journal. Genevieve Healy of the University of Queensland in Australia drew on data from 4,757 people who wore tiny accelerometers to measure their movement patterns for seven consecutive days. Once again, greater amounts of sedentary time were linked to a wide range of blood markers for heart disease and metabolic disorders.

But the accelerometers were also able to record breaks as short as a minute that interrupted sedentary time. The number of breaks taken by the subjects throughout the week ranged from 99 to 1,258, and the researchers found that those who took the most breaks were significantly healthier (for example, their waistlines were 4.1 centimetres smaller) than those who took the fewest breaks - independent of the total amount of sedentary time they accumulated.

While the general message from this research is clear - take frequent, short breaks from desks and couches - more specific guidance will have to wait for the results of new studies being planned by Mr. Saunders and others to directly measure how many hours at a time you can stay seated before metabolic changes begin.

Until then, we're left with interim solutions - such as the $30 foot-pedal device that Mr. Saunders invested in last fall while preparing for his doctoral exams, when he realized he was spending 14 hours a day sitting at a desk reading about the dangers of sitting at a desk.

"It just sits under my desk and I pedal, I'd say about half [an]hour out of every hour. Very low intensity, but it's engaging the muscles in my legs and the muscles in my lower back," he says.

Story continues below advertisement

"I have no idea whether or not this is making a difference, but it's plausible … and in the absence of any other options, I'm going to keep doing it."

Your Globe

Build your personal news feed

  1. Follow topics and authors relevant to your reading interests.
  2. Check your Following feed daily, and never miss an article. Access your Following feed from your account menu at the top right corner of every page.

Follow the author of this article:

Follow topics related to this article:

View more suggestions in Following Read more about following topics and authors
Report an error Editorial code of conduct
Due to technical reasons, we have temporarily removed commenting from our articles. We hope to have this fixed soon. Thank you for your patience. If you are looking to give feedback on our new site, please send it along to feedback@globeandmail.com. If you want to write a letter to the editor, please forward to letters@globeandmail.com.

Welcome to The Globe and Mail’s comment community. This is a space where subscribers can engage with each other and Globe staff. Non-subscribers can read and sort comments but will not be able to engage with them in any way. Click here to subscribe.

If you would like to write a letter to the editor, please forward it to letters@globeandmail.com. Readers can also interact with The Globe on Facebook and Twitter .

Welcome to The Globe and Mail’s comment community. This is a space where subscribers can engage with each other and Globe staff. Non-subscribers can read and sort comments but will not be able to engage with them in any way. Click here to subscribe.

If you would like to write a letter to the editor, please forward it to letters@globeandmail.com. Readers can also interact with The Globe on Facebook and Twitter .

Welcome to The Globe and Mail’s comment community. This is a space where subscribers can engage with each other and Globe staff.

We aim to create a safe and valuable space for discussion and debate. That means:

  • Treat others as you wish to be treated
  • Criticize ideas, not people
  • Stay on topic
  • Avoid the use of toxic and offensive language
  • Flag bad behaviour

If you do not see your comment posted immediately, it is being reviewed by the moderation team and may appear shortly, generally within an hour.

We aim to have all comments reviewed in a timely manner.

Comments that violate our community guidelines will not be posted.

UPDATED: Read our community guidelines here

Discussion loading ...

To view this site properly, enable cookies in your browser. Read our privacy policy to learn more.
How to enable cookies