Scientists have named the acceptable time for long sitting

Prolonged sitting can affect muscle function even if a person is physically active at other times of the day. The researchers found that when sitting for a long time, the activity of the thigh muscles gradually decreases and after about 25 minutes approaches the minimum level. About why it is important to take breaks during sedentary work and how even small movements can affect your health — in the Izvestia article.

After 25 minutes of sitting, the muscles work less

Researchers from Swinburne University of Technology in Australia studied muscle activity during everyday sitting. 84 people participated in the study, and scientists analyzed 7,684 periods of sitting. The work was published in the journal npj Exercise Medicine and Health (EMH).

It turned out that as the duration of continuous sitting increases, the thigh muscles become less active. After about 25 minutes, the fraction of time that the sensors recorded muscle activity decreased to almost minimal values. People who usually sat for longer periods of time had lower muscle activity levels than those who stopped sitting more often.

How can inactivity affect your health

A decrease in muscle activity may be accompanied by a deterioration in blood flow and a decrease in glucose uptake from the blood by muscle tissue. These processes are considered as possible mechanisms linking prolonged sitting with metabolic disorders and an increased risk of cardiovascular diseases and type 2 diabetes.

At the same time, the scientists did not measure exactly how the duration of each sitting period affected the development of diseases in the participants. The work was primarily devoted to changes in muscle activity in everyday life. Therefore, the results help explain a possible risk mechanism, but they do not mean that after 25 minutes of sitting, a person necessarily has health problems.

Even small movements matter.

Not every period of sitting is accompanied by equally low muscle activity. Some activities, such as talking to friends or working at a desk, may involve small involuntary movements. There may be fewer such movements while watching a movie in stillness.

These connections have been identified in other studies of sedentary behavior. However, the new work does not prove that movements while sitting alone lead to weight loss or prevent diseases. It shows that periods of sitting vary in the level of muscle activity and that this difference can have implications for metabolism.

Why regularly interrupt sedentary work

Researchers believe that one of the easiest ways to maintain muscle activity is to get up and move periodically. According to their calculations, if a person spends about 10 hours a day sitting and interrupts sitting every 25 minutes, the total muscle activity during these periods can increase by about an hour and a half. The authors estimate that this corresponds to a decrease in the proportion of time with minimal muscle activity by about 10% during the waking period.

At the same time, scientists do not claim that exactly 25 minutes is the universal limit of safe sitting. The study revealed a pattern in muscle activity, and further work is needed to assess how much regular breaks help prevent diseases. The authors believe that it is especially important to study how the frequency and intensity of movement during the day affect the metabolism.