{"url":"https://whatshealthyandwhy.com/sedentary-time/is-sitting-the-new-smoking","path":"/sedentary-time/is-sitting-the-new-smoking","alternates":{"json":"https://whatshealthyandwhy.com/api/articles/sedentary-time/is-sitting-the-new-smoking.json","markdown":"https://whatshealthyandwhy.com/sedentary-time/is-sitting-the-new-smoking.md"},"topic":{"slug":"sedentary-time","name":"Sedentary Time","url":"https://whatshealthyandwhy.com/sedentary-time"},"slug":"is-sitting-the-new-smoking","order":1,"title":"Is Sitting the New Smoking?","question":"Is sitting really 'the new smoking,' and what can you do about it?","answer":"No: sitting is far less risky than smoking, but long sitting likely raises risk, and an hour of daily moderate activity seems to offset it.","description":"Long sitting raises health risks, but far less than smoking does. What big cohorts show, how much activity offsets it, and whether standing desks help.","confidence":3,"confidenceNote":"Large cohorts and harmonized meta-analyses agree on direction, but they are observational and cannot set a safe sitting limit; trials are short and measure blood sugar.","evidenceSummary":{"rctCount":1,"observationalCount":3,"metaAnalysisCount":6,"totalParticipants":"1,000,000+","replicated":true,"newestStudyYear":2022},"category":{"categoryTitle":"How to Live","categorySlug":"how-to-live","subcategoryName":"Exercise & Movement","subcategorySlug":"exercise","url":"https://whatshealthyandwhy.com/explore/how-to-live/exercise"},"actions":["Break up long sits with 2 minutes of walking every 20 to 30 minutes. In a small crossover trial, this lowered blood sugar and insulin after a meal [4].","Aim for the WHO target of 150–300 minutes of moderate activity a week [12]: in a 149,077-adult cohort, meeting it largely erased the extra risk linked to sitting [6].","Use a standing desk as a change of position, not a fix. Walking breaks lowered post-meal blood sugar more than standing breaks [5]."],"cautions":["People with heart or lung disease, joint problems, pregnancy or a disability should get tailored advice before raising activity; WHO guidance has specific recommendations for these groups [12].","Do not swap sitting for standing all day. In one Ontario cohort, mostly-standing jobs went with about double the heart-disease risk of mostly-sitting jobs [11]."],"simpleText":"No. Sitting is not the new smoking: current smokers are about 2.8 times as likely to die in a given period as people who never smoked, while the heaviest sitters have a much smaller excess risk [1]. Even so, sitting more than about 8 hours a day goes with higher death rates, mostly in people who are not active [2][3]. Roughly an hour of moderate activity a day seems to cancel the extra risk [3].","mediumText":"How it works\n\nWhy sitting may matter. Resting muscles use little glucose. After a meal, blood sugar and insulin stay higher when you sit for hours than when you break the sitting up. In a trial of 19 overweight adults, 2-minute walking breaks every 20 minutes cut the post-meal blood-sugar and insulin response compared with sitting straight through [4]. A pooled analysis of seven such crossover trials found light walking breaks beat standing breaks for both glucose and insulin, and neither changed systolic blood pressure [5].\n\nHow much is too much. Across 34 studies and about 1.3 million people, the extra risk of dying from any cause was small up to 8 hours of sitting a day (about 1% per added hour) and rose to about 4% per added hour beyond that. For cardiovascular death the turning point was about 6 hours, and for TV viewing about 3 to 4 hours [2].\n\nActivity offsets much of it. In a harmonized analysis of more than 1 million adults, people who sat over 8 hours a day but did about 60 to 75 minutes of moderate activity daily had no clear excess risk. High TV time was only partly offset [3]. In the 45 and Up Study (149,077 adults), sitting mattered mainly among those with no moderate-to-vigorous activity; meeting the guidelines largely erased the link [6].\n\nLight movement counts. Accelerometer data from 36,383 adults showed any activity, even light, went with lower mortality, and the most sedentary quarter had about 2.6 times the risk of the least sedentary [7]. Long unbroken sitting seems worse: in 7,985 adults, the longest average sitting bouts carried higher risk than shorter ones [8].\n\nStanding desks. Sit-stand desks cut office sitting by about 100 minutes per workday in the short term, but the evidence is low quality and runs out after about a year [9]. Standing burns only about 0.15 kcal per minute more than sitting [10], and a job spent mostly standing was not safer for the heart [11].\n\nPractical rule. Move every 20 to 30 minutes, add a brisk walk after meals (see Daily Steps and After-Meal Walks), and build toward the WHO target of 150 to 300 minutes of moderate activity a week. WHO could not set a sitting limit, but it recommends reducing sedentary time [12]. For desk setup, see The Modern Posture Crisis.","deepText":"The evidence in detail\n\nSitting versus smoking. A public-health commentary compared effect sizes: the most recent meta-analysis of sedentary behavior gave a hazard ratio of 1.22 (95% CI 1.09 to 1.41) for all-cause mortality, while current smokers had a relative risk of 2.80 in men and 2.76 in women, and 4.08 to 4.41 for heavy smokers. In absolute terms, the heaviest sitters had about 190 excess deaths per 100,000 people a year versus more than 2,000 for the heaviest smokers [1].\n\nHarmonized cohorts. The Lancet analysis pooled 13 cohorts with sitting data (1,005,791 people, 84,609 deaths, follow-up 2 to 18 years). Against a reference of under 4 hours of sitting and the most active quartile, those sitting over 8 hours and in the least active quartile had a hazard ratio of 1.59 (95% CI 1.52 to 1.66). Those who sat over 8 hours but were in the most active quartile had 1.04 (0.99 to 1.10). Even people who sat least but were least active had 1.27 (1.22 to 1.31). For TV viewing (six cohorts, 465,450 people), 3 or more hours a day raised mortality regardless of activity, except in the most active group, where only 5 or more hours did (HR 1.16, 1.05 to 1.28) [3]. In the 45 and Up Study (149,077 adults followed for 8.9 years), among people reporting no moderate-to-vigorous activity the all-cause HR for more than 8 versus under 4 hours of sitting was 1.52 (1.13 to 2.03), while the link was weak and inconsistent in those meeting 150 minutes a week or more [6].\n\nDevice-measured cohorts. Pooling 8 accelerometer studies (36,383 adults, median follow-up 5.8 years, 2,149 deaths), mortality hazard ratios across increasing sedentary-time quarters were 1.28, 1.71 and 2.63 (the last: 1.94 to 3.56), and across increasing total activity quarters 0.48, 0.34 and 0.27 [7]. In a US national cohort (7,985 adults aged 45 or older, 340 deaths in about 4 years), the most sedentary quartile had an HR of 2.63 (1.60 to 4.30) and the longest-bout quartile 1.96 (1.31 to 2.93) [8]. A dose-response meta-analysis of 34 studies confirmed thresholds near 6 to 8 hours of total sitting [2].\n\nTrials. The 19-person crossover trial found post-meal glucose areas under the curve of 5.2 and 4.9 mmol/L per hour with light and moderate walking breaks, versus 6.9 with uninterrupted sitting [4]. The seven-trial meta-analysis found standing breaks lowered post-meal glucose modestly (effect size -0.31) and walking breaks more (-0.72 for glucose, -0.83 for insulin) [5]. These are single-day studies of blood markers, not heart attacks or deaths. A Cochrane review of 34 workplace studies (3,397 participants) found sit-stand desks reduced sitting by 100 minutes a day at up to 3 months (95% CI 84 to 116) and 57 minutes at 3 to 12 months, with low-quality evidence and no longer follow-up [9]. A meta-analysis of 46 studies (1,184 people) found standing used 0.15 kcal per minute more than sitting, or about 54 kcal a day for 6 hours of standing in a 65 kg person [10].\n\nNull and conflicting results. Sitting data are mostly self-reported or device-measured for about a week, and healthier people sit less, so reverse causation and confounding are likely. Accelerometer analyses treat sitting and activity as trading time, so sitting effects cannot be separated cleanly from missing activity [7]. The Ontario cohort of 7,320 workers found predominantly standing jobs had about twice the heart-disease risk of sitting jobs over 12 years, which is a different exposure from short spells of standing at a desk [11]. WHO's expert group concluded evidence was insufficient to quantify a sedentary threshold [12].\n\nBottom line (confidence 3 of 5). Sitting is not smoking, but more than about 8 hours a day likely adds risk, mainly if you are otherwise inactive, and about an hour of moderate activity a day seems to offset it. Interrupting sitting helps blood sugar in the short term. Treat standing desks as a modest aid, and put effort into walking and regular movement instead.","deepTruncated":false,"references":[{"id":"1","title":"Evaluating the Evidence on Sitting, Smoking, and Health: Is Sitting Really the New Smoking?","authors":"Vallance JK, Gardiner PA, Lynch BM, et al.","year":2018,"journal":"Am J Public Health","pmid":"30252516","url":"https://pubmed.ncbi.nlm.nih.gov/30252516/"},{"id":"2","title":"Sedentary behaviour and risk of all-cause, cardiovascular and cancer mortality, and incident type 2 diabetes: a systematic review and dose response meta-analysis","authors":"Patterson R, McNamara E, Tainio M, et al.","year":2018,"journal":"Eur J Epidemiol","pmid":"29589226","url":"https://pubmed.ncbi.nlm.nih.gov/29589226/"},{"id":"3","title":"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","authors":"Ekelund U, Steene-Johannessen J, Brown WJ, et al.","year":2016,"journal":"Lancet","pmid":"27475271","url":"https://pubmed.ncbi.nlm.nih.gov/27475271/"},{"id":"4","title":"Breaking up prolonged sitting reduces postprandial glucose and insulin responses","authors":"Dunstan DW, Kingwell BA, Larsen R, et al.","year":2012,"journal":"Diabetes Care","pmid":"22374636","url":"https://pubmed.ncbi.nlm.nih.gov/22374636/"},{"id":"5","title":"The Acute Effects of Interrupting Prolonged Sitting Time in Adults with Standing and Light-Intensity Walking on Biomarkers of Cardiometabolic Health in Adults: A Systematic Review and Meta-analysis","authors":"Buffey AJ, Herring MP, Langley CK, et al.","year":2022,"journal":"Sports Med","pmid":"35147898","url":"https://pubmed.ncbi.nlm.nih.gov/35147898/"},{"id":"6","title":"Sitting Time, Physical Activity, and Risk of Mortality in Adults","authors":"Stamatakis E, Gale J, Bauman A, et al.","year":2019,"journal":"J Am Coll Cardiol","pmid":"31023430","url":"https://pubmed.ncbi.nlm.nih.gov/31023430/"},{"id":"7","title":"Dose-response associations between accelerometry measured physical activity and sedentary time and all cause mortality: systematic review and harmonised meta-analysis","authors":"Ekelund U, Tarp J, Steene-Johannessen J, et al.","year":2019,"journal":"BMJ","pmid":"31434697","url":"https://pubmed.ncbi.nlm.nih.gov/31434697/"},{"id":"8","title":"Patterns of Sedentary Behavior and Mortality in U.S. Middle-Aged and Older Adults: A National Cohort Study","authors":"Diaz KM, Howard VJ, Hutto B, et al.","year":2017,"journal":"Ann Intern Med","pmid":"28892811","url":"https://pubmed.ncbi.nlm.nih.gov/28892811/"},{"id":"9","title":"Workplace interventions for reducing sitting at work","authors":"Shrestha N, Kukkonen-Harjula KT, Verbeek JH, et al.","year":2018,"journal":"Cochrane Database Syst Rev","pmid":"29926475","url":"https://pubmed.ncbi.nlm.nih.gov/29926475/"},{"id":"10","title":"Differences of energy expenditure while sitting versus standing: A systematic review and meta-analysis","authors":"Saeidifard F, Medina-Inojosa JR, Supervia M, et al.","year":2018,"journal":"Eur J Prev Cardiol","pmid":"29385357","url":"https://pubmed.ncbi.nlm.nih.gov/29385357/"},{"id":"11","title":"The Relationship Between Occupational Standing and Sitting and Incident Heart Disease Over a 12-Year Period in Ontario, Canada","authors":"Smith P, Ma H, Glazier RH, et al.","year":2018,"journal":"Am J Epidemiol","pmid":"29020132","url":"https://pubmed.ncbi.nlm.nih.gov/29020132/"},{"id":"12","title":"World Health Organization 2020 guidelines on physical activity and sedentary behaviour","authors":"Bull FC, Al-Ansari SS, Biddle S, et al.","year":2020,"journal":"Br J Sports Med","pmid":"33239350","url":"https://pubmed.ncbi.nlm.nih.gov/33239350/"}],"wordCount":1129,"source":{"path":"src/content/topics/sedentary-time/is-sitting-the-new-smoking.md"},"citeAs":"“Is sitting really 'the new smoking,' and what can you do about it?.” What's Healthy and Why. https://whatshealthyandwhy.com/sedentary-time/is-sitting-the-new-smoking","notice":"General information backed by peer-reviewed research, not medical advice."}