Just 20-25 minutes of daily physical activity may be enough to offset the increased risk of death due to a sedentary lifestyle, according to research published in the British Journal of Sports Medicine.

Adults in developed countries spend an average of nine to ten hours daily sitting, mostly during working hours. However, a particularly sedentary lifestyle is associated with an increased risk of death.

The researchers collected individual participant data from four groups of people from 2003 to 2019 who were fitted with activity trackers to see if physical activity might modify the relationship between sedentary time and death, and by how much physical activity may affect this risk.

The analysis included just under 12,000 people aged 50 and over who had been followed for at least two years and had provided details of factors that may influence the condition, such as gender, education level, weight, height, smoking history, alcohol consumption , current or past cardiovascular disease, cancer or diabetes.

In total, 5,943 people spent less than 10.5 hours daily sitting, 6,042 people had 10.5 or more hours of sedentary life. Linkage with death registers showed that over an average period of five years, 805 (7%) people died, of whom 357 (6%) spent less than 10.5 hours sitting each day and 448 of them 10.5 or more hours.

Analysis of the data showed that sitting for more than twelve hours a day was associated with a 38% increased risk of death compared to a daily figure of eight hours, for those who got less than 22 minutes of moderate to vigorous physical activity per day. More than 22 minutes of daily moderate-to-vigorous physical activity was associated with a lower risk of death.

At the same time, higher daily rates of physical activity are associated with a lower risk, regardless of the amount of time spent sitting each day. An extra ten minutes a day was associated with a 15% lower risk of death in those who spent less than 10.5 hours sedentary, and a 35% lower risk in those who spent more than 10.5 hours sedentary each day.

On the other hand, light-intensity physical activity was associated with a lower risk of death only among those with a heavy sedentary lifestyle (twelve or more hours daily).

The researchers clarify that they did not take into account factors that may affect health, such as diet and general health.