Sitting time
Pooled cohorts link more sitting and TV time to more deaths, heart disease and type 2 diabetes, with risk rising most above 6 to 8 hours of sitting or 3 to 4 hours of TV a day. About 60 to 75 minutes of daily moderate activity removed the sitting link, not the TV link. Breaks lowered post-meal blood sugar.
- Status
- A daily life factor, not a product.
- Also called
- sedentary time, sedentary behavior, sedentary behaviour, sitting, prolonged sitting, TV time, television viewing, desk job, sitting is the new smoking, breaking up sitting, standing desk, sit-stand desk
- Studied for
- living longer, heart health, diabetes prevention, blood sugar, weight, back and neck pain, offsetting a desk job with exercise
Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on
Shown to help9
- StrongLinked to more deaths with more sitting in pooled cohorts, independent of exercise, with risk rising mainly above about 7 to 8 hours a day.
- StrongLinked to no higher death rate from sitting in people doing about 60 to 75 minutes of moderate activity a day, in a harmonized analysis of over a million adults.
- StrongLinked to more deaths with more TV time in pooled cohorts, rising above about 3 to 4 hours a day, a link exercise weakened but did not remove.
- StrongLinked to more cardiovascular disease and deaths from it with more sitting or TV time in pooled cohorts, with risk rising above about 6 hours of sitting a day.
- StrongLinked to more type 2 diabetes with more sitting or TV time in pooled cohorts, with a steady rise and no threshold.
- StrongShown to lower blood sugar and insulin after meals when long sitting was broken up with short activity breaks, in two meta-analyses of short trials.
- ModerateShown to cut sitting by about an hour a day and lower HbA1c 0.17%, body fat and waist size in trials of people with chronic conditions.
- ModerateShown to cut sitting at work by about 100 minutes a workday over the first 3 months with sit-stand desks, in a Cochrane review rating the evidence low in quality.
- LimitedOne trial in office workers found less neck and shoulder pain after 3 months of a program to cut sitting, and no change in back pain.
Reported risks1
What it was studied for, and what was found
Shown to help9
Death from any cause
Linked to more deaths with more sitting in pooled cohorts, independent of exercise, with risk rising mainly above about 7 to 8 hours a day.
Compared with people with less sedentary time, with physical activity held equal [1]; each hour less of sitting, within intervals of 0 to 3, over 3 to 7 and over 7 hours a day [2]; each hour less of sitting a day [3]; the least sedentary quarter of people [4]
The numbers and sources
- Effect
- Sedentary time was linked to higher all-cause mortality after adjusting for physical activity (HR 1.240, 95% CI 1.090 to 1.410), more so at low activity [1]. Each extra hour of sitting carried an HR of 1.00 between 0 and 3 hours, 1.02 between 3 and 7 hours and 1.05 above 7 hours, an estimated 34% higher risk at 10 hours a day [2]. Each hour added 1% to risk up to 8 hours a day and 4% above 8 hours [3]. With sitting measured by device, the most sedentary quarter had an HR of 2.63 (95% CI 1.94 to 3.56) against the least sedentary [4].
- Population
- 13 studies in the mortality analysis, from 47 articles [1]. 595,086 adults with 29,162 deaths in 6 cohorts [2]. 1,331,468 participants in 34 studies [3]. 36,383 adults, mean age 62.6, in 8 cohorts with device-measured sitting [4].
- Sources
- [1], [2], [3], [4]
- Caveats
- Observational, and sitting was self-reported in all but one study in one review [1]. Confounding is likely, and reverse causation is possible because people who are ill sit more. The device-measured cohorts were mostly older women, and the size of their link is larger than in the self-report cohorts [4].
Whether exercise offsets sitting
Linked to no higher death rate from sitting in people doing about 60 to 75 minutes of moderate activity a day, in a harmonized analysis of over a million adults.
Compared with people sitting under 4 hours a day in the most active quarter [5]; people with less sedentary time, with physical activity held equal [1]; each hour less of sitting, with and without adjustment for activity [2]
The numbers and sources
- Effect
- People sitting over 8 hours a day but in the most active quarter (over 35.5 MET-hours a week) had no higher mortality (HR 1.04, 95% CI 0.99 to 1.10) than those sitting under 4 hours in the same quarter. People sitting under 4 hours in the least active quarter had higher mortality (HR 1.27, 95% CI 1.22 to 1.31). The highest risk was in the least active people sitting over 8 hours (HR 1.59, 95% CI 1.52 to 1.66) [5]. Sitting-linked risk was more pronounced at lower activity levels [1], and moderate to vigorous activity weakened the sitting link [2].
- Population
- 1,005,791 adults in 13 cohorts with 84,609 deaths, followed 2 to 18.1 years [5]. 47 articles [1]. 595,086 adults [2].
- Sources
- [5], [1], [2]
- Caveats
- Observational, with self-reported sitting and activity. The active quarter's level, about 60 to 75 minutes of moderate activity a day, is well above what most adults do [5].
TV time and death
Linked to more deaths with more TV time in pooled cohorts, rising above about 3 to 4 hours a day, a link exercise weakened but did not remove.
Compared with each 2 hours less of TV a day [6]; each hour less of TV a day [3]; people in the lowest of four TV-time groups and the most active quarter [5]
The numbers and sources
- Effect
- Each 2 hours of TV a day was linked to 13% higher mortality (RR 1.13, 95% CI 1.07 to 1.18), with risk rising above 3 hours a day [6]. After adjusting for activity, each hour of TV added 3% to risk up to 3.5 hours a day and 6% above that [3]. Watching 3 hours or more was linked to higher mortality at every activity level except the most active, where only 5 hours or more carried a higher risk (HR 1.16, 95% CI 1.05 to 1.28) [5].
- Population
- 26,509 people with 1,879 deaths in 3 cohorts [6]. 34 studies [3]. 465,450 people with 43,740 deaths in 6 cohorts [5].
- Sources
- [6], [3], [5]
- Caveats
- Observational. TV time often goes with snacking, lower income and poorer health, which may explain part of the link.
Heart disease
Linked to more cardiovascular disease and deaths from it with more sitting or TV time in pooled cohorts, with risk rising above about 6 hours of sitting a day.
Compared with people with less sedentary time, with physical activity held equal [1]; each hour less of sitting or TV a day [3]; each 2 hours less of TV a day [6]
The numbers and sources
- Effect
- Sedentary time was linked to cardiovascular death (HR 1.179, 95% CI 1.106 to 1.257) and new cardiovascular disease (HR 1.143, 95% CI 1.002 to 1.729) [1]. For cardiovascular death, each hour of sitting carried no added risk up to 6 hours (RR 1.01, 95% CI 0.99 to 1.02) and 4% more above 6 hours. Each hour of TV carried 8% more above 4 hours [3]. Each 2 hours of TV was linked to 15% more fatal or nonfatal cardiovascular disease (RR 1.15, 95% CI 1.06 to 1.23) [6].
- Population
- 14 studies of cardiovascular disease and diabetes [1]. 34 studies [3]. 34,253 people with 1,052 cases in 4 cohorts [6].
- Sources
- [1], [3], [6]
- Caveats
- Observational. Heterogeneity in designs and in how sitting was measured was marked [1]. Confounding and reverse causation cannot be excluded.
Type 2 diabetes
Linked to more type 2 diabetes with more sitting or TV time in pooled cohorts, with a steady rise and no threshold.
Compared with people with less sedentary time, with physical activity held equal [1]; each hour less of sitting or TV a day [3]; each 2 hours less of TV a day [6]
The numbers and sources
- Effect
- Sedentary time was linked to new type 2 diabetes (HR 1.910, 95% CI 1.642 to 2.222) [1]. Each hour of total sitting carried 1% more risk (RR 1.01, 95% CI 1.00 to 1.01) and each hour of TV 9% more (RR 1.09, 95% CI 1.07 to 1.12), both linear [3]. Each 2 hours of TV was linked to 20% more type 2 diabetes (RR 1.20, 95% CI 1.14 to 1.27) [6].
- Population
- 14 studies [1]. 34 studies [3]. 175,938 people with 6,428 cases in 4 cohorts [6].
- Sources
- [1], [3], [6]
- Caveats
- Observational. Body weight, diet and snacking while watching TV are likely confounders.
Blood sugar after meals when sitting is broken up
Shown to lower blood sugar and insulin after meals when long sitting was broken up with short activity breaks, in two meta-analyses of short trials.
Compared with continuous sitting [7]; prolonged sitting without breaks [8]
The numbers and sources
- Effect
- Activity breaks lowered post-meal glucose (SMD -0.54, 95% CI -0.70 to -0.37) and insulin (SMD -0.56, 95% CI -0.74 to -0.38), with larger glucose effects at higher BMI. Triglycerides fell slightly (SMD -0.26), with possible publication bias. Against one continuous exercise bout of matched energy, breaks lowered glucose slightly more (SMD -0.26) [7]. A second review found lower glucose (d -0.36, 95% CI -0.50 to -0.21) and insulin (d -0.37), and no change in triglycerides (d 0.06, 95% CI -0.15 to 0.26) [8].
- Population
- 37 studies in adults who were metabolically healthy or impaired [7]. 20 studies in apparently healthy people [8].
- Sources
- [7], [8]
- Caveats
- Most trials lasted a single day in a laboratory. Post-meal readings are not fasting glucose or HbA1c, and a day's effect does not show long-term change. The two reviews disagree on triglycerides.
Long-term programs to cut sitting
Shown to cut sitting by about an hour a day and lower HbA1c 0.17%, body fat and waist size in trials of people with chronic conditions.
Compared with control interventions [9]; control offices whose workers were told to behave as usual [10]
The numbers and sources
- Effect
- Lifestyle programs cut sedentary time by 64 minutes a day (95% CI -91 to -38). HbA1c fell 0.17% (95% CI -0.30 to -0.04), body fat 0.66 percentage points and waist circumference 1.52 cm against control groups [9]. In office workers, a workplace program cut sitting by 71 minutes per 8-hour workday at 1 month and 48 minutes at 3 months, and body fat was 0.61 percentage points lower at 3 months [10].
- Population
- 18 randomized trials in people with overweight, type 2 diabetes, heart, neurological or musculoskeletal disease [9]. 317 office workers in 19 offices, cluster randomized [10].
- Sources
- [9], [10]
- Caveats
- Programs often added counseling and activity, so the effect of less sitting alone cannot be separated out. Follow-up was months, not years.
Sitting at work with sit-stand desks
Shown to cut sitting at work by about 100 minutes a workday over the first 3 months with sit-stand desks, in a Cochrane review rating the evidence low in quality.
Compared with sit desks [11]
The numbers and sources
- Effect
- Sit-stand desks cut sitting at work by 100 minutes a workday at up to 3 months (95% CI -116 to -84, 10 studies) and by 57 minutes at 3 to 12 months (95% CI -99 to -15, 2 studies). Total sitting fell 82 minutes a day. Walking strategies, information and counseling alone showed no significant short-term change [11].
- Population
- 3,397 workers in 34 studies in high-income countries [11].
- Sources
- [11]
- Caveats
- The review found no evidence beyond 12 months, and rated most evidence low to very low in quality [11]. Sitting less at work does not by itself show a health change.
Neck and shoulder pain
One trial in office workers found less neck and shoulder pain after 3 months of a program to cut sitting, and no change in back pain.
Compared with control offices whose workers behaved as usual [12]
The numbers and sources
- Effect
- At 3 months, the odds of neck and shoulder pain were lower in the program group (OR 0.52, 95% CI 0.30 to 0.92), with no difference at 1 month. Back and limb pain did not differ. Total pain score fell slightly [12].
- Population
- 317 office workers in 19 offices [12].
- Sources
- [12]
- Caveats
- Pain was a secondary outcome, self-reported by workers who knew their group.
Amounts studied
Cohorts asked about total daily sitting or TV time. The harmonized analysis grouped sitting as under 4, 4 to 6, 6 to 8 and over 8 hours a day, and physical activity in quarters, the top one above 35.5 MET-hours a week, about 60 to 75 minutes of moderate activity a day [5]. The dose-response review placed the rise in risk above 6 to 8 hours of sitting and 3 to 4 hours of TV a day [3]. One harmonized review measured sedentary time by accelerometer [4].
Break trials replaced continuous sitting of up to a day with short bouts of standing, walking or cycling, for example 2 minutes of walking every 30 minutes [7][8]. Workplace trials used sit-stand desks, prompts and multicomponent programs for weeks to 12 months [11][10]. Lifestyle programs in people with chronic conditions combined counseling, self-monitoring and technology [9].
Risks
Reported risks1
Prolonged standing at work
Linked to about twice the heart disease of mainly seated jobs in one cohort, and to more hospital treatment for varicose veins in another.
The numbers and sources
- How common
- How often is not known: the sources give no rate.
- Effect
- Jobs involving mainly standing were associated with about twice the risk of new heart disease over 12 years compared with jobs involving mainly sitting, after adjusting for many confounders [13]. Jobs requiring standing or walking at least 75% of the time were linked to more hospital treatment for varicose veins (pooled RR 1.78, 95% CI 1.19 to 2.68) compared with all other jobs [14].
- Population
- 7,320 employed adults in Ontario, followed about 12 years [13]. 5,647 Danish workers aged 20 to 59, with 111 hospitalizations over 12 years [14].
- Sources
- [13], [14]
- Caveats
- Observational. Standing jobs differ from desk jobs in pay, shift work and physical strain. These studies are about all-day standing jobs, not trials of standing desks, and neither gives a rate per worker.
Claims tested and not found
- That enough exercise cancels out a lot of TV time. In the most active quarter, people watching 5 hours or more of TV a day still had higher mortality (HR 1.16, 95% CI 1.05 to 1.28) [5].
- That workplace walking strategies cut sitting. Walking strategies did not change workplace sitting at short-term (-15 minutes a day, 95% CI -50 to 19) or medium-term follow-up [11].
- That information and counseling alone cut sitting at work in the first months. They produced no significant change at short-term follow-up (-19 minutes a day, 95% CI -57 to 19) [11].
Related
Sources
- Biswas A, Oh PI, Faulkner GE, et al. Sedentary time and its association with risk for disease incidence, mortality, and hospitalization in adults: a systematic review and meta-analysis. Annals of Internal Medicine. 2015. https://doi.org/10.7326/M14-1651
- Chau JY, Grunseit AC, Chey T, et al. Daily sitting time and all-cause mortality: a meta-analysis. PLOS ONE. 2013. https://doi.org/10.1371/journal.pone.0080000
- Patterson R, McNamara E, Tainio M, et al. Sedentary behaviour and risk of all-cause, cardiovascular and cancer mortality, and incident type 2 diabetes: a systematic review and dose response meta-analysis. European Journal of Epidemiology. 2018. https://doi.org/10.1007/s10654-018-0380-1
- Ekelund U, Tarp J, Steene-Johannessen J, et al. Dose-response associations between accelerometry measured physical activity and sedentary time and all cause mortality: systematic review and harmonised meta-analysis. BMJ. 2019. https://doi.org/10.1136/bmj.l4570
- Ekelund U, Steene-Johannessen J, Brown WJ, et al. Does physical activity attenuate, or even eliminate, the detrimental association of sitting time with mortality? A harmonised meta-analysis of data from more than 1 million men and women. The Lancet. 2016. https://doi.org/10.1016/S0140-6736(16)30370-1
- Grøntved A, Hu FB. Television viewing and risk of type 2 diabetes, cardiovascular disease, and all-cause mortality: a meta-analysis. JAMA. 2011. https://doi.org/10.1001/jama.2011.812
- Loh R, Stamatakis E, Folkerts D, et al. Effects of Interrupting Prolonged Sitting with Physical Activity Breaks on Blood Glucose, Insulin and Triacylglycerol Measures: A Systematic Review and Meta-analysis. Sports Medicine. 2020. https://doi.org/10.1007/s40279-019-01183-w
- Saunders TJ, Atkinson HF, Burr J, et al. The Acute Metabolic and Vascular Impact of Interrupting Prolonged Sitting: A Systematic Review and Meta-Analysis. Sports Medicine. 2018. https://doi.org/10.1007/s40279-018-0963-8
- Nieste I, Franssen WMA, Spaas J, et al. Lifestyle interventions to reduce sedentary behaviour in clinical populations: A systematic review and meta-analysis of different strategies and effects on cardiometabolic health. Preventive Medicine. 2021. https://doi.org/10.1016/j.ypmed.2021.106593
- Danquah IH, Kloster S, Holtermann A, et al. Take a Stand! A multi-component intervention aimed at reducing sitting time among office workers, a cluster randomized trial. International Journal of Epidemiology. 2016. https://doi.org/10.1093/ije/dyw009
- Shrestha N, Kukkonen-Harjula KT, Verbeek JH, et al. Workplace interventions for reducing sitting at work. Cochrane Database of Systematic Reviews. 2018. https://doi.org/10.1002/14651858.CD010912.pub5
- Danquah IH, Kloster S, Holtermann A, et al. Effects on musculoskeletal pain from "Take a Stand!", a cluster-randomized controlled trial reducing sitting time among office workers. Scandinavian Journal of Work, Environment and Health. 2017. https://doi.org/10.5271/sjweh.3639
- Smith P, Ma H, Glazier RH, et al. The Relationship Between Occupational Standing and Sitting and Incident Heart Disease Over a 12-Year Period in Ontario, Canada. American Journal of Epidemiology. 2018. https://doi.org/10.1093/aje/kwx298
- Tüchsen F, Hannerz H, Burr H, Krause N. Prolonged standing at work and hospitalisation due to varicose veins: a 12 year prospective study of the Danish population. Occupational and Environmental Medicine. 2005. https://doi.org/10.1136/oem.2005.020537