Swinburne Study Flags 25-Minute Sitting Tipping Point

A Swinburne team tracked muscle activity during more than 7,000 everyday sitting periods using sensor-equipped shorts. The study, led by Dr. Christian Brakenridge and published in npj Exercise Medicine and Health, found that muscle activity dropped when sitting continued past 25 minutes without a break.

Walking or exercising between sitting periods was linked with more active muscles during later sitting. Brakenridge says reduced activity may occur alongside poorer blood flow and less blood-sugar uptake, patterns that can add to heart disease and type 2 diabetes risk. Sitting that includes small movements, such as working at a desk or talking with friends, may be less harmful than remaining still while watching a movie.

The researchers describe frequent movement breaks as a simple way to interrupt long sitting. In an example involving 10 hours of daily sitting, activity every 25 minutes could add about 1.5 hours of muscle activity and represent a 10% decrease in inactivity during waking hours. The findings support moving regularly, but they do not prove that 25 minutes is a disease-risk threshold.