Even light-intensity physical activity could substantially reduce mortality risk, suggests a new research published this week in the BMJ.
While previous studies have repeatedly suggested that physical activity is good for health and long life, guidelines for physical activity are mainly based on self-reported activity and it is not clear how much activity and at what intensity is needed to protect health.
To investigate this further, researchers at the Norwegian School of Sport Sciences in Oslo examined the dose-response associations between accelerometer-assessed total physical activity, different intensities of physical activity and sedentary time and all-cause mortality. Data from eight high-quality studies involving 36,383 adults aged at least 40 years (average age 62.6 years) were included. During follow-up, 2,149 participants died.
The researchers found that any physical activity, regardless of intensity, was associated with a lower risk of mortality, with a non-linear dose-response. The maximal risk reduction for total physical activity (hazard ratio [RR] 0.34; 95% 0.27-0.43) was observed at about 300 counts per minute.
In contrast, spending 9.5 hours or more each day sedentary was associated with a statistically significant increased risk of death.
The authors suggest the public health message might simply be “sit less and move more and more often".