• Posted October 25, 2023

Even a Little Physical Activity Can Offset a Day Spent Sitting

Even a little exercise can counter the harms of sitting all day, a new study suggests.

Prolonged sitting raises your odds for an early death, but just 20 to 25 minutes of physical activity a day may offset that risk, researchers found.

"If people, for any reason, are sedentary for most of the day, small amounts of physical activity will still lower the risk of death substantially," said lead researcher Edvard Sagelv, from UiT The Arctic University of Norway, in Tromso.

That can even include light intensity exercise like cleaning.

For the study, Sagelv and his team reviewed data on nearly 12,000 older adults. They found that being sedentary for over 12 hours a day -- perhaps either watching TV or sitting at a desk -- raised the risk of early death, but only in those getting less than 22 minutes of moderate exercise a day.

"Individuals doing more than 22 minutes of moderate-to-vigorous physical activity per day, the equivalent of the World Health Organization's 150 minutes per week guidelines, had no increased risk of death with more sedentary time," Sagelv said.

This study, however, can't prove that exercise alone lowered the risk of premature death, only that there appears to be an association.

Still, the study "is a reaffirmation of our fundamental need to move our bodies if they are to reward us with vitality," said Dr. David Katz, a specialist in preventive and lifestyle medicine, and president of the True Health Initiative. He wasn't involved in the research.

In much of the developed world, adults spend nine to 10 hours sitting, mostly at their jobs. Many strategies have been tried to reduce sedentary time, especially at work, Sagelv said.

Some workplaces are providing "sit-to-stand workstations to reduce sitting time or having standing areas instead of sitting space," he said.

Providing safe spaces to exercise outside of work is more challenging, Sagelv added, citing a need for safe areas for cycling and walking or having green areas in cities.

"More public money devoted to providing safe spaces for exercise will prevent more disease and eventually premature death," he said.

The investigators collected data on participants in the Norwegian Tromsø Study, the Swedish Healthy Ageing Initiative, the Norwegian National Physical Activity Survey and the U.S. National Health and Nutrition Examination Survey. All participants were at least 50 years old and used fitness tracking devices.

About 6,000 people spent less than 11 hours sitting every day, and 6,000 spent 11 or more hours on their backsides.

Over an average of five years, 7% of the study participants died. An analysis of the activity trackers showed that folks who sat more than 12 hours a day had a 38% higher risk of dying during the study period, compared with those who sat for much of the day but exercised about 22 minutes a day.

However, more than 22 daily minutes of moderate-to-vigorous physical activity was linked with a lower risk of death, Sagelv said.

For example, an extra 10 minutes of daily exercise was associated with a 15% lower risk of death in those who logged fewer than 11 sedentary hours every day, and a 35% lower risk among those who clocked more than 11 sedentary hours, he explained.

Sagelv said that "moderate and vigorous physical activity, the intensity, is not as high as it seems from a population perspective, it is breathing a little bit heavier than at rest."

Examples are brisk walking, walking at a normal pace up a hill, cycling at a normal pace, doing gardening work, or playing with kids, he noted.

Sagelv also said it's never too late to start exercising to reap the benefits. "The more active you are, the longer you avoid loss of muscles and loss of heart fitness," he explained.

"There are studies from the beginning of the 2000s that showed that 70-year-olds doing endurance training their entire life had the same cardiorespiratory fitness level as a sedentary 20-year-old. You can simply train yourself to get younger," Sagelv said.

The report was published Oct. 24 in the British Journal of Sports Medicine.

Exercise improves health by getting more oxygen to your muscles, including the heart and lungs, said Dr. Christopher Tanayan, director of sports cardiology at Lenox Hill Hospital in New York City.

If worrisome symptoms develop, such as shortness of breath, you should let your doctor know.

"If there's something wrong with your heart then you are essentially forcing your heart to pump and then if you have a limitation of blood flow to the heart itself, then you will develop symptoms you can present to your doctor and it gets taken care of earlier," Tanayan said.

More information

The U.S. Centers for Disease Control and Prevention has more on the benefits of exercise.

SOURCES: Edvard Sagelv, PhD, UiT The Arctic University of Norway, Tromso; Christopher Tanayan, MD, director, sports cardiology, Lenox Hill Hospital, New York City; David Katz, MD, specialist, preventive and lifestyle medicine, and president, True Health Initiative; British Journal of Sports Medicine, Oct. 24, 2023