Adults who spend much of their time sitting have increased mortality risk — and the risk is even higher when the sedentary time is uninterrupted — according to a prospective study in the Annals of Internal Medicine.
U.S. researchers followed nearly 8000 adults aged 45 and older for roughly 4 years. Participants wore an accelerometer for at least 10 hours on at least 4 days to measure sedentary behavior.
During follow-up, 340 participants died. Both greater total amount of sedentary time and longer duration of individual bouts of sedentary time were significantly associated with increased mortality risk — even after adjustment for moderate-to-vigorous physical activity and cardiovascular risk factors.
Participants who spent more than 12.5 hours daily in sedentary time and also had sedentary bouts lasting 30 minutes or longer had the greatest mortality risk. Accordingly, the authors suggest that “interrupting sedentary time every 30 minutes may protect against the health risks incurred by prolonged sedentariness.”