What you've heard
Sitting is the new smoking
Verdict
Exaggerated about tenfold
Exaggerated about tenfold. Break up sitting, but above all, move more.
Is sitting the new smoking?
Exaggerated about tenfold. Break up sitting, but above all, move more.
Long sitting is linked to higher death rates, but the comparison with cigarettes is not close. Against never-smokers, the heaviest smokers suffer more than two thousand extra deaths per hundred thousand people a year; the heaviest sitters, against the lightest, about two hundred. That extra risk can be bought back: in pooled data on more than a million people, those who sat over eight hours a day but did roughly an hour or more of moderate activity daily had no clear excess risk. Five or more hours of daily television stayed linked to higher risk even in the most active. Standing all day is no cure either: it burns barely more than sitting, and long hours of it are linked to varicose veins. Sit-stand desks cut workplace sitting at first, but their trials measured sitting, not disease.8
Where the book tests it
What the book recommends instead
Break up sitting every half hour
ProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.How: stand and walk for two to five minutes, whether a lap of the house, a trip to the water tap or the long way to the bathroom. Set a timer, or tie it to something that already happens, like the end of each call. Why: walking breaks blunt the rise in blood sugar after meals, and walking beats standing.
Sources
- 8.Vallance, J.K., Gardiner, P.A., Lynch, B.M., D'Silva, A., et al. (2018). "Evaluating the evidence on sitting, smoking, and health: is sitting really the new smoking?" American Journal of Public Health, 108(11), 1478-1482. https://doi.org/10.2105/AJPH.2018.304649 ; Ekelund, U., Steene-Johannessen, J., Brown, W.J., Fagerland, M.W., et al. (2016). "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, 388(10051), 1302-1310. https://doi.org/10.1016/S0140-6736(16)30370-1 ; Saeidifard, F., Medina-Inojosa, J.R., Supervia, M., Olson, T.P., et al. (2018). "Differences of energy expenditure while sitting versus standing: a systematic review and meta-analysis." European Journal of Preventive Cardiology, 25(5), 522-538. https://doi.org/10.1177/2047487317752186 ; Ahmadi, M.N., Coenen, P., Straker, L., and Stamatakis, E. (2024). "Device-measured stationary behaviour and cardiovascular and orthostatic circulatory disease incidence." International Journal of Epidemiology, 53(6), dyae136. https://doi.org/10.1093/ije/dyae136 ; Shrestha, N., Kukkonen-Harjula, K.T., Verbeek, J.H., Ijaz, S., et al. (2018). "Workplace interventions for reducing sitting at work." Cochrane Database of Systematic Reviews, 12, CD010912. https://doi.org/10.1002/14651858.CD010912.pub5 . The smoking and sitting figures are more than 2,000 against about 190 extra deaths per 100,000.
Note numbers are those of Chapter 3, The Body That Walks.
This verdict is one of the "What you've heard" boxes in Chapter 3, The Body That Walks, where the book tests the claims people repeat against the studies behind them.
Educational content, not medical advice. Disclaimer.