Move more to stay fit in pandemic era, WHO advises

All adults should do a minimum of 150 minutes of vigorous physical activity per week, even more vital for well-being and mental health in the COVID-19 era, the World Health Organization (WHO) said on Wednesday in its first guidance in a decade.

It recommended that children and adolescents have an average of one hour of daily physical exercise and limit time in front of electronic screens.

And people of all ages must compensate for growing sedentary behaviour with physical activity to ward off disease and add years to their lives, WHO said, launching its "Every Move Counts" campaign.

"Increasing physical activity not only helps prevent and manage heart disease, Type-2 diabetes and cancer, it also reduces symptoms of depression and anxiety, reduces cognitive decline including Alzheimer's and improves memory," Ruediger Krech, WHO director for health promotion, told a news briefing.

Yet one in four adults and a "staggering" four out of five adolescents do not get enough physical activity, which can include walking, cycling, gardening and cleaning, WHO said.

"These guidelines emphasize what many are experiencing during the COVID restrictions that are applied all over the world. And that is that being active every day is good not only our bodies, but also our mental health," said Fiona Bull, head of WHO's physical activity unit.

"Phone a friend and do classes online together, help your family members, do it as a family. And when you can, get outside," she said.

Offset harms of sitting too much

Research into the ill-effects of sedentary behaviour (defined in this guideline as 10 or more hours) has grown in the past decade, leading to the new advice, Bull said.

That advice is to limit sedentary time and to do more activity to offset the time people do spend not moving, she said, particularly those who spend long hours in office-based work environments. 

"For children we also recommend they limit sedentary time, particularly screen time."

Pregnant women and postpartum mothers are now included in the recommendations of 150 to 300 minutes of moderate to vigorous aerobic activity per week for adults.

This provides health benefits for both the mother and baby, according to Juana Willumsen, a WHO technical officer.

"For example there is a 30 per cent reduction in gestational diabetes amongst women who are physically active during pregnancy," she said.

Adults above 65 are advised to add muscle strengthening and activities focusing on balance and co-ordination to help prevent falls later.

Start small and build up

Devices worn on the wrist or hip that track physical activity are helpful for all, Bull said.

"Monitoring how active you are is very good feedback," she said. "That is important because we tend to think we might be more active. We tend to underestimate how much time we spend sedentary."

Those unable to meet the recommendations should start small and gradually build up the frequency, intensity and duration of their physical activity, the researchers suggested.

Dr. Ali Zentner of Vancouver appreciated the positive approach of the new guidelines, which she wasn't involved in writing. She said to think of activity rather than serious exercise at first. 

"Walk the walls of your house," Zentner said. "Walk from the kitchen to the living room and back and do it 10 times and that's good."

The research involved more than 44,000 people from four countries wearing activity trackers.