Apparently sitting for long periods of time is detrimental to your health and radically increases your risk of death. Is this true? For all the desk workers, long-distance truck drivers and couch potatoes out there, let’s find out.
Sitting has now become this generation’s pariah, as smoking was for the last generation. Apparently sitting for long periods of time is detrimental to your health and radically increases your risk of death. Is sitting all day killing you? For all the desk workers, long-distance truck drivers and couch potatoes out there, let’s find out.
I’m Not Sedentary… Or Maybe I am!
Sedentary behaviour is usually defined as time spent sitting or lying down while awake. (1) We already know that adults should be getting a minimum of 150 minutes of exercise per week (2), however the WHO cites that insufficient physical activity is a leading risk factor in 10% of all deaths worldwide. Almost 80% of the world’s adolescent population are insufficiently physically active, with 25% of all adults globally not receiving adequate physical activity. (3)
A meta-analysis published in the Annals of Internal Medicine in January 2015 showed that a sedentary lifestyle was independently associated with negative health outcomes, including an increase in cardiovascular and cancer mortality. (4)
The NHS even published that having a desk job doubles a person’s risk of having a heart attack. (1)
A 15-year observational study, published in May 2015, followed over 77,000 post-menopausal women comparing low and high sitting-time maintainers. The study reported that those who were considered low sitting-time maintainers had a drastically reduced risk of cancer mortality and all-cause mortality, at 48% and 51% respectively. (5)
Another meta-analysis published in the Journal of National Cancer Institute found that high levels of sedentary time were associated with an increased risk of colon, endometrial and lung cancer, though no relation was found with cancers of the breast, rectum, ovaries, prostate, stomach, esophagus, testes, renal cell and Non-Hodgkin’s Lymphoma. (6)
Another study reported that women who sat for more than eight hours per day showed an increased risk of dying within the next nine years. (7)
You’re joking, is sitting really that bad for you?
What is even more concerning is that a recent study in the British Medical Journal found that prolonged sitting increases the risk of serious illness and death despite exercising. (8) However, another study found that older adults who replaced at least one hour of sitting time with an activity lowered both their cardiovascular and their all-cause mortality. (9)
An expert statement published in June 2015 by the British Journal of Sports Medicine recommended that full-time desk-workers should aim for a total accumulation of four hours of standing or light activity each day. (10)
In light of this newly identified high risk behaviour, some workplaces have started introducing sit-stand desks (SSD), which have been shown to reduce office sitting time and provide other health benefits. (11), (12) Participants who use SSD’s also reported greater alertness and energy at work, (13) and breaking up prolonged sitting has been shown to also reduce blood pressure. (14)
The Long and the Short of Sitting
Who would have thought that your innocent-lookinng, extra-comfy, lumbar supported chair is a potential death trap? Of course, further research is necessary in order for more accurate outcomes and clearer endpoints to be understood.
Most of the evidence to date is derived from observational studies, which rely on self-reported sedentary times. As with all self-reported studies, the reliability is dependent on the individual participants.
It is evident that excessive sedentary time is associated with increased morbidity and mortality, but what remains unclear is just exactly how much time is too much sitting.
In essence, what we really need to do is to get up and move more: Take a few laps of the office and say hi to some co-workers; do five squats when you get that sluggish afternoon, or try some push-ups while you’re waiting for dinner to cook!
On that note, readers, I will now be getting up from the computer to break up my sitting time.
Yours in health,
- NHS News [Internet]. Having a desk job doubles risk of heart attack; 2012 Oct 15 [cited 2015 Jul 12]; [about 2 screens]. Available from: http://www.nhs.uk/news/2012/10October/Pages/Having-desk-job-doubles-risk-of-heart-attack.aspx
- NHS News [Internet]. Why sitting too much is bad for your health; 2014 Oct 10 [cited 2015 Jul 12]; [about 3 screens]. Available from: http://www.nhs.uk/livewell/fitness/pages/sitting-and-sedentary-behaviour-are-bad-for-your-health.aspx
- World Health Organization [Internet]. Media Centre: Physical Activity; 2015 Jan [cited 2015 Jul 12]; [about 2 screens]. Available from: http://www.who.int/mediacentre/factsheets/fs385/en/
- Biswas A, Oh P, Faulkner G, Bajaj R, Silver M, Mitchel M, Alter D. Sedentary time and its association with risk for disease incidence, mortality, and hospitalization in adults: a systematic review and meta-analysis. Ann Intern Med [Internet]. 2015 Jan 20 [cited 2015 Jul 12];162(2):123-132. Available from: http://annals.org/article.aspx?articleid=2091327
- Lee J, Kuk J, Ardern C. The relationship between changes in sitting time and mortality in post-menopausal US women. J Public Health (Oxf) [Internet]. 2015 May 1 [cited 2015 Jul 19];Epub ahead of print. Available from: http://www.ncbi.nlm.nih.gov/pubmed/25935896
- Schmid D, Leitzmann M. Television viewing and time spent sedentary in relation to cancer risk: a meta-analysis. J Natl Cancer Inst [Internet]. 2014 Jun 16 [cited 2015 Jul 19];106(7). Available from: http://www.ncbi.nlm.nih.gov/pubmed/24935969
- Pavey T, Peeters G, Brown W. Sitting-time and 9-year all-cause mortality in older women. Br J Sports Med [Internet]. 2015 Jan [cited 2015 Jul 19];49(2):95-9. Available from: http://www.ncbi.nlm.nih.gov/pubmed/23243009
- Mayor S. Prolonged sitting increases risk of serious illness and death regardless of exercise, study finds. BMJ [Internet]. 2015 Jan 19 [cited 2015 Jul 19];350:h306. Available from: http://www.ncbi.nlm.nih.gov/pubmed/25646739
- Matthews C, Moore SC, Sampson J, Blair A, Xiao Q, Keadle SK, Hollenbeck A et al. Mortality Benefits for Replacing Sitting Time with Different Physical Activities. Med Sci Sports Exerc [Internet]. 2015 Jan 26 [cited 2015 Jul 19];Epub ahead of print. Available from:
- Buckley J, Hedge A, Yates T, Copeland R, Loosemore M, Hamer M, Bradley G et al. The sedentary office: an expert statement on the growing case for change towards better health and productivity. Br J Sports Med [Internet]. 2015 Jun 1 [cited 2015 Jul 19];Epub ahead of print. Available from: http://www.ncbi.nlm.nih.gov/pubmed/26034192
- Chau J, Daley M, Dunn S, Srinivasan A, Do A, Bauman A, van der Ploeg H. The effectiveness of sit-stand workstations for changing office workers’ sitting time: results from the Stand@Work randomized controlled trial pilot. Int J Behav Nutr Phys Act [Internet]. 2014 Oct 8 [cited 2015 Jul 19];11:127. Available from: http://www.ncbi.nlm.nih.gov/pubmed/25291960
- Pronk N, Katz A, Lowry M, Payfer J. Reducing occupational sitting time and improving worker health: the Take-a-Stand Project, 2011. Prev Chronic Dis [Internet]. 2012 [cited 2015 Jul 15];9:E154. Available from: http://www.ncbi.nlm.nih.gov/pubmed/23057991
- Dutta N, Walton T, Pereira M. Experience of switching from a traditional sitting workstation to a sit-stand workstation in sedentary office workers. Work [Internet]. 2014 Nov 25 [cited 2015 Jul 19];Epub ahead of print. Available from: http://www.ncbi.nlm.nih.gov/pubmed/25425587
- Larsen R, Kingwell B, Sethi P, Cerin E, Owen N, Dunstan D. Breaking up prolonged sitting reduces resting blood pressure in overweight/obese adults. Nutr Metab Cardiovasc Dis [Internet]. 2014 Sep [cited 2015 Jul 19];24(9):976-82. Available from: http://www.ncbi.nlm.nih.gov/pubmed/24875670