Even a little exercise linked to a longer life
Researchers examined data from 10 previously published studies that used accelerometers that track movement to measure the exact amount of active and sedentary time spent by more than 36,000 older adults. After an average follow-up period of 6.7 years, a total of 2,149 people died, or about 6% of the participants.
Compared to people who got virtually no exercise, people who got the most physical activity were 73% less likely to die during the study, regardless of how intensely they worked out. With even a little exercise, people were 52% less like to die.
When researchers looked only at people who did light workouts, they again found that even a little bit of low-intensity exercise was associated with a 40% lower risk of death during the study compared with doing nothing at all. People who got the most light-intensity exercise were 62% less likely to die.
“The finding that higher levels of light-intensity physical activity reduce the risk of death is novel and suggests that all physical activity counts,” said Ulf Ekelund, lead author of the study and a researcher at the Norwegian School of Sport Sciences and the Norwegian Institute of Public Health in Oslo.
“This is of particular importance for elderly and those who may not be able to participate in physical activity at moderate and higher intensities,” Ekelund said by email. “The simple take-home message is to sit less, move more, and move more often.”
Physical inactivity has long been linked to an increased risk of premature death and a wide variety of chronic health problems, but much of this evidence has been based on surveys that might not provide an accurate picture of how much exercise people really get, the review team writes in The BMJ.
In the current analysis, participants were 63 years old, on average. All of them wore accelerometers for at least 10 hours a day for four or more days to track how much they moved, the intensity of their activity levels and how much time they were sedentary and not moving at all.
People who were sedentary for 10 hours a day were 48% more likely to die during the study than people who moved more. Twelve hours a day of sedentary time was associated with an almost tripled risk of death during the study.
When researchers excluded people who died within the first two years of follow-up – who might have been sicker than others, explaining their inactivity – the results didn’t change.
One limitation of the study is that it looked at men and women combined, making it impossible to determine if there are any sex-based differences in the connection between activity levels and longevity. Participants were also middle-aged and older, so it’s unclear if results would be similar for younger adults.
“By reducing sedentary time people increase activity, therefore, it is likely that both are not independent factors and that they represent two sides of the same coin,” said Jochen Klenk, author of an editorial accompanying the study and a researcher the Institute of Epidemiology and Medical Biometry at Ulm University in Germany.
“Based in the results of the paper, is seems that any level of intensity is beneficial,” Klenk said by email.