Question: In the new year, I am determined to pay more attention to my health. What is one of the best things I can do to make me healthier?
Answer: If you’re like most people, you spend too much time on your bottom. Many of us sit for much of the day at work and when we come home at night, we plop down in front of a TV or some other screen. Scores of studies have found that this sedentary lifestyle is taking a huge toll on our health, contributing to the development of heart disease, diabetes, cancer and other chronic illnesses.
But an intriguing study, published last year in the Annals of Internal Medicine, found that it’s not just the total amount of sitting time that’s the problem. Rather, it’s how long you remain inactive at a stretch that seems to make things worse.
The study involved 8,000 middle-aged and older adults. On average, they sat for 12.3 hours over a typical day. During four years of follow-up, 340 of the participants died.
When the researchers did a deep dive on the numbers, they discovered that the volunteers who normally kept their sitting to less than 30 minutes at a time had a 55 percent lower risk of death than those who tended to sit for longer stretches.
“Even though two people may sit for the same amount of time throughout the day, the one who sits for longer bouts has a greater risk of premature death,” says Dr. Keith Diaz, the lead author of the study and an assistant professor of behavioural medicine at Columbia University in New York.
The results of the study suggest that taking a “movement break” every half-hour mitigates some of the negative effects of the sedentary time, he adds.
Diaz advises us to get up and move every 30 minutes. “It doesn’t matter what type of movement you do,” he explains. “A nice casual stroll down the hall is enough to lower some of the risks incurred by sitting.”
The researchers aren’t sure why shorter bouts of sitting appear to be less harmful than extended inactivity. But they have a few theories.
For instance, it’s possible that prolonged sitting leads to elevated blood-glucose levels. “If you are inactive, your muscles don’t need energy to move,” he says. As a result, sugar isn’t removed from the bloodstream “causing a cascade of changes” that may lead to various health problems—including increasing the risk of diabetes.
What’s more, sitting for a long period causes blood to pool in the legs, which may over time stress blood vessels and undermine the cardiovascular system.
Dr. Diaz is quick to say that he is not a fan of so-called standing desks, the current office furniture fad meant to counteract the deleterious effects of sitting.
“Unfortunately, there is not really much scientific evidence to support the claim that standing is a better alternative to sitting,” he says.
“You’re not moving so you are not activating your muscles much,” he adds. “Standing is not the same as exercise.” In fact, prolonged standing could actually be bad for you because it also causes blood to pool in the legs.
For that reason, he believes movement breaks are the real antidote to sitting—and other experts agree.
“Your body is designed to be mobile,” says Dr. Murray Waldman, a hospitalist at St. John’s Rehab, a division of Sunnybrook Health Sciences Centre.
“There is absolutely no downside to it. Even if you have arthritis or another chronic pain condition, it is still better to move.”
Of course, not everyone has the job freedom to get up and go for a walk. But doing things like contracting your leg muscles, pointing your toes up and down, or other stationary exercises may help. “The trick is to keep your calf muscles activated,” says Dr. Waldman.
Outside the workplace, it’s also important to take regular movement breaks in your spare time. Planting yourself in front of a TV after consuming a big dinner might be even worse than a day of inactivity at your place of employment.
At least at work, you may occasionally get up to speak with a colleague, go for a cup of coffee, or walk to a meeting. At home, there may be nothing motivating you to rise from the couch—other than to get a snack from the kitchen.
So how do you remind yourself to take a movement break? Get yourself a timer, or use your smartphone, and set an alarm to go off every half-hour while you’re awake. This approach won’t be practical in every situation, but it might help nudge you in the right direction some of the time.
After all, every minute that you move contributes to your overall health. Adults should aim for at least 150 minutes a week of moderate to vigorous physical activity.
It used to be thought that you had to exercise for a minimum of 10 consecutive minutes to reap any health benefits. But many experts now say that even isolated bouts of activity are good for you.
“Whenever you have an opportunity to move, do it,” says Dr. Diaz. It all adds up.
Sunnybrook’s Patient Navigation Advisor provides advice and answers questions from patients and their families. This article was originally published on Sunnybrook’s Your Health Matters, and it is reprinted on Healthy Debate with permission. Follow Paul on Twitter @epaultaylor.
If you have a question about your doctor, hospital or how to navigate the health care system, email AskPaul@Sunnybrook.ca