A study published online in the American Journal of Epidemiology Jan. 14 suggests any physical movement, whether it’s short, long, intense or mild, counteracts the negative cardiovascular effects of sitting for long periods.
Around a quarter of adults spend more than eight hours a day sedentary, lead author Keith Diaz, PhD, and coauthors said in the journal, whether that’s laying on the couch at home, sitting at a desk job or bent over a computer for long periods of time. In the U.S. alone, adults are spending between 11 and 12 hours per day sedentary.
“Evidence indicates that time spent in sedentary behavior is associated with incident cardiovascular disease and mortality,” Diaz and colleagues wrote. “Experimental studies, furthermore, show that accumulation of sedentary time in prolonged, uninterrupted bouts elicits greater detrimental cardiometabolic effects compared with sedentary behavior that is periodically interrupted, suggestive that prolonged sedentary bouts might be the most hazardous type of sedentary behavior.
"Importantly, the risk conferred by prolonged sedentariness is eliminated only by high levels of moderate to vigorous physical activity.”
For their present work, Diaz et al. considered 7,999 individuals who’d taken part in a national study of racial and regional disparities in stroke between 2009 and 2013. Subjects wore activity monitors for at least four days to record their average amount and intensity of physical activity while awake. Taking into account the death rate among participants through 2017, the researchers estimated how substituting half an hour of sitting each day with physical activity would affect participants’ risk of early death.
Diaz and his team found subjects who replaced 30 minutes of sedentary time with low-intensity physical activity, like walking, saw a 17 percent decreased risk of early death. In subjects who opted for a more vigorous activity, like a spin class or morning run, the reduction was as high as 35 percent.
The researchers said even just a minute or two of activity provided a health benefit.
“These findings might be helpful to inform public health strategies for reducing the health risks incurred by sedentary behavior and suggest that short sedentary bouts still carry risk and are not alone a healthful alternative to prolonged sedentary bouts,” they wrote. “Instead, physical activity of any intensity (and of any length of time) is needed to mitigate the mortality risks incurred by sedentary time, with greater benefit incurred with more intense activity.”
Diaz said in a release his team’s future work will focus on the specific cardiovascular consequences, like MI or heart failure, of sedentary versus active behavior.
After graduating from Indiana University-Bloomington with a bachelor’s in journalism, Anicka joined TriMed’s Chicago team in 2017 covering cardiology. Close to her heart is long-form journalism, Pilot G-2 pens, dark chocolate and her dog Harper Lee.