For how we live.
A short walk after eating blunts the post-meal blood-sugar spike. Trials in people with type 2 diabetes and in healthy adults agree, and light walking beats standing, which beats sitting still.
Standing up every half hour is common desk advice. A meta-analysis of seven trials found brief standing breaks trim post-meal glucose a little, but short light-walking breaks cut both glucose and insulin far more.
Walking pads promise movement without leaving your desk. A trial found walking while working slowed typing but did not harm cognition; a second found hourly walking cut post-meal glucose and blood pressure.
The global target is an average of 60 minutes a day of moderate-to-vigorous activity, plus muscle-strengthening. Most adolescents miss it: in 2016, 81% worldwide were insufficiently active, and girls more than boys.
A harmonised meta-analysis of over a million adults found high sitting time raised mortality — but about 60 to 75 minutes a day of activity erased that risk. Being inactive, not the chair itself, did most of the damage.
A harmonised meta-analysis of over a million adults found 60 to 75 minutes of daily moderate activity erased the extra death risk tied to sitting more than eight hours. The catch is how much activity that is.
The WHO sets clear screen-time limits by age: none under two, an hour or less from two. The evidence behind them is real but modest — and the direction of cause and effect is not as simple as it sounds.
Leisure exercise reliably protects the heart. Physical activity done for a living shows mixed or even adverse associations — and some meta-analyses find higher mortality in men with the most physically demanding jobs.
A Cochrane review found sit-stand desks reliably reduce workplace sitting, but graded the evidence low quality and could not tie it to better health. WHO backs cutting sedentary time but set no number.
A harmonised meta-analysis of more than a million people found the association between sitting time and death disappeared in the most active quarter. In the least active, it did not disappear at all.