Norwegian review of 36,000 cases links more activity overall, light or intensive, with lower risk of death
Nicola Davis – The Guardian
Even a small increase in light activity, such as washing dishes, a little gentle gardening, or shuffling around the house, might help stave off an early death among older adults, researchers say.
The latest study backs up previous research suggesting that reducing time spent sedentary and replacing it even with light movement is beneficial. It says higher levels of any physical activity help ward off an early grave.
“It is important for elderly people, who might not be able to do much moderate-intensity activity, that just moving around and doing light-intensity [activity] [will have] strong effects and is beneficial,” said Ulf Ekelund, a professor and first author of the study at the Norwegian School of Sport Sciences.
However, the study finds that there is more “bang for your buck” if you engage in intense activity compared with light activity. A short stint of intense activity is viewed as beneficial as much longer periods of lesser activity.
Emmanuel Stamatakis, professor of physical activity, lifestyle and population health at the University of Sydney, who was not involved in the study, said movement should be re-engineered into our daily lives.
“People could seek to add more physical activity of any intensity to their daily routines when their circumstances and surroundings allow. But the onus is more on governments to put forward policies that will enable and empower people to move more as part of their daily routines,” he said, noting that this could include building infrastructure to promote walking and cycling.
Published in the BMJ, the latest research involved a review of eight studies encompassing a total of more than 36,000 people with an average age of almost 63 years. Participants were followed for about five to six years; 2,149 deaths were recorded.
Crucially, all the studies involved monitoring the physical activity of individuals who had activity trackers, and the studies did not rely on self-reporting, which, the experts noted, could be unreliable.
For each study, participants were split into four equal-sized groups, based on the total amount of time spent active, and the risk of death assessed, taking into account factors such as age, sex, body-mass index, and socioeconomic status. This was then repeated for an amount of activity at different levels of intensity. The results were analysed together to give an overview.
The team found a greater volume of activity overall was linked to a lower risk of death. The results held for different intensities of activity.
Compared with those who managed the least light physical activity, of about 200 minutes a day, those who clocked up about 258 minutes a day had a 40% lower risk of death, and those who managed about 308 minutes had a 56% lower risk.
Meanwhile, the group with the highest levels of light physical activity – achieving about 380 minutes a day – had a 62% lower risk of death than the group that did the least. The team noted that this was about twice as big an effect as previously thought, possibly due to more accurate data collection.
For moderate to vigorous activity, the trend was similar, even when levels of sedentary time were taken into account. Compared with those who managed the least, of about 90 seconds a day, those who managed about six minutes a day had a 36% lower risk of death, while those who managed most, about 38 minutes a day, had a 48% lower risk of death.
The team said the study supported the message “sit less and move more and more often”.
However, the study had limitations. It only looked at the situation for middle age and older adults, most of whom lived in the US or Europe, and some of the effect could be due to those people with a higher risk of death being less likely to engage in physical activity. Physical activity levels also were only measured over one period of time.
Gavin Sandercock, of the University of Essex, said the results suggested moving more brought bigger benefits than simply reducing sedentary time, another factor measured in the study. “This study reinforces the important message that getting the least active people to do even just a little bit more physical activity can have have important public health benefits,” he said.