How many hours of sitting a day is too many? The World Health Organization’s 2020 guidelines include recommendations on sedentary time, but set no number of hours — they say a threshold was considered but the evidence was insufficient. Instead they say two things: sit less and move at any intensity, and if you sit a lot, do more than the recommended 150–300 minutes. We quoted the paper presenting the guidelines as written.
1. Sedentary behaviour means any waking behaviour at 1.5 METs or lower while sitting, reclining or lying. Watching TV and desk work are typical examples (our examples).
2. There is no numeric limit. “Although specifying a quantitative threshold on the amount of sedentary behaviour was strongly considered, there was insufficient evidence.”
3. Instead, the guidelines recommend: adults limit sedentary time and replace it with activity of any intensity, and to offset high sedentary time, aim for more than the recommended moderate-to-vigorous activity.
WHO 2020 recommendations — adults (18–64) and older adults
- Adults should limit the amount of time spent being sedentary. Replacing it with physical activity of any intensity (including light) provides health benefits.
- To help reduce the detrimental effects of high levels of sedentary behaviour, adults should aim to do more than the recommended levels of moderate-to-vigorous activity.
- The same sedentary recommendations apply to adults aged 65 and over.
The “recommended levels” — aerobic activity
| Intensity | Weekly recommendation | Going further |
|---|---|---|
| Moderate | 150–300 minutes | Over 300 minutes for additional benefits |
| Vigorous | 75–150 minutes | Over 150 minutes |
| Mixed | An equivalent combination | — |
The 2020 guidelines express the adult recommendation as a 150–300 minute range and mention going beyond it. When those who sit a lot are told to do “more than the recommended levels,” the upper end of this table is the reference (our reading).
Children and teenagers: screen time
For ages 5–17, the guidelines say to limit sedentary time, “particularly the amount of recreational screen time.” Screen limits for under-5s are in how much exercise children need.
Applying it to a day — our example
| Change | Example | Guideline sentence behind it |
|---|---|---|
| Break up sitting | Take calls standing, stairs between meetings | Even light intensity helps |
| Walk part of the commute | Get off one stop early | Any intensity helps |
| Raise weekly activity | 150 → 300 minutes a week (about 43 a day) | More than the recommended levels |
Our examples, not a prescription. 300 ÷ 7 ≈ 43 minutes (our arithmetic). The guidelines give no figure such as “stand up every so many minutes.”
Checklist
- ☐ When in the day do you sit longest?
- ☐ Slot light movement into those stretches
- ☐ Already at 150 moderate minutes a week? Move toward 300
- ☐ Cut children’s recreational screen time
Questions that remain
Is sitting 8 hours a day dangerous?
The 2020 WHO guidelines set no such number, explaining that the evidence was insufficient. Material asserting a specific hour limit is not relying on these guidelines.
If I exercise, is the sitting fine?
The guidelines recommend both separately — meet the activity recommendation and sit less — and add that those who sit a lot should do more than the recommended amount.
Sources
- Bull FC et al. — World Health Organization 2020 guidelines on physical activity and sedentary behaviour, Br J Sports Med 2020 (checked 1 October 2026). Definition of sedentary behaviour (1.5 METs or lower), adult and older-adult sedentary recommendations, “insufficient evidence,” adult 150–300 and 75–150 minutes and beyond, recreational screen time for 5–17, and “some physical activity is better than none.”
- Our own working. About 43 minutes a day and the daily examples are ours.
Where to check further
- Exercise intensity — talk test on exercise intensity.
- Legs swollen from sitting — leg swelling stretches.
Written on 1 October 2026. The recommendations are from the WHO guidelines; the examples and arithmetic are ours.
