Sedentariness: A Need for a Definition
- 1Université Clermont Auvergne, UFR de Psychologie, Sciences Sociales, Sciences de l'Éducation, CNRS, LaPSCo, Clermont-Ferrand, France
- 2Université Clermont Auvergne, CNRS, LaPSCo, Physiological and Psychosocial Stress, University Hospital of Clermont-Ferrand, CHU Clermont-Ferrand, Preventive and Occupational Medicine, WittyFit, Clermont-Ferrand, France
- 3Faculty of Health, School of Exercise Science, Australian Catholic University, Melbourne, VIC, Australia
- 4Université Clermont Auvergne, CNRS, LaPSCo, Clermont-Ferrand, France
Sedentary behavior is a growing field of research which is now recognized as a public health issue (1). Sedentary comes from the latin term “sedere,” which means “to sit.” Many researchers have shown that remaining seated for prolonged periods of time can lead to several detrimental health effects at the physiological level [see (2) for a systematic review], such as an increased risk of developing cardiovascular disease (3–5), type 2 diabetes (3, 4, 6), obesity (4, 7), some cancers (8, 9), or musculoskeletal disorders (10, 11). It also has detrimental effects at the psychological level, such as depression (12–14), anxiety (14–16), or cognitive decline [(17–19); for a review, see 20]. However, there is no consensus in the physiological results (for contradictory results concerning cardiovascular disease and type 2 diabetes, see 21, 22, respectively), and psychological results are still not consistent for depression (23), anxiety (24), or cognitive decline (17). More research is therefore needed to further understand the implications of sedentary behavior on both physiological (25) and psychological health (17).
Sedentary behavior has been defined in many ways over the years, but mostly by using energy expenditure, i.e., any behavior where energy expenditure is strictly below 2 METs (Metabolic Equivalent Tasks) (26), or between 1 MET and 1.8 METs (27). However, that criterion alone is not enough to clarify what sedentary behavior is. Indeed, standing has an energy cost close to sitting (28), without causing any of the detrimental health effects of sedentary behavior. For instance, breaking up prolonged sitting times by standing for a few minutes has a positive impact on postprandial glucose metabolism (29–31). However, there is no consensus for these results (32–34). Posture therefore must be taken into account to distinguish a standing up position from sedentary behavior. Currently, the terminology consensus project from the sedentary behavior research network [SBRN, (35)] defines sedentary behavior as “any waking behavior characterized by an energy expenditure ≤ 1.5 METs, while in a sitting, reclining or lying posture.” This definition excludes a standing position as sedentary behavior and grants a better understanding of what sedentary behaviors are, and what differentiates them from others.
However, this recent definition may not be enough to reveal the complexity of sedentariness as a way of life. Indeed, it refers to behaviors adopted at a specific time but without providing any long-term information. It does not grant a better understanding of what a sedentary lifestyle is and what its characteristics are. Thus, it fails to define what a sedentary lifestyle is, whereas such a definition has been given for physical (in)activity. According to the WHO recommendations (36), healthy adults “should do at least 150 minutes of moderate-intensity aerobic physical activity throughout the week, or do at least 75 minutes of vigorous-intensity aerobic physical activity throughout the week, or an equivalent combination of moderate-and vigorous-intensity activity. Aerobic activity should be performed in bouts of at least 10 minutes duration.” Yet around one third of the world's population (37) and 55 to 70% of the US population over 65 (38) do not meet these guidelines, which is detrimental to health. For example, in the general population, physical inactivity is independently related to an increased risk of obesity (39), type 2 diabetes (40, 41), some cancers (42, 43), shortened life expectancy (42, 44), and risks of mental health problems (45, 46). In Canada, physical inactivity represents nearly 3% of the overall health care costs (47) and has been recognized as a worldwide economic burden (48). These cut-offs in physical activity allow a distinction to be made between physically active individuals and physically inactive ones. They would also be useful in the definition of sedentary behaviors, but they have not yet been integrated.
Only taking into account the energy expenditure and the posture is not enough when one is interested in the lifestyle of an individual. A sedentary lifestyle cannot be reduced to physical inactivity. Regardless of the confusion between the two terms (4, 49, 50), physical inactivity and sedentary behavior can be considered as independent, because their physiological consequences on health are not the same. For example, sedentary behavior leads to an increased risk of mortality (1, 51–53), irrespective of the amount of physical activity practiced. A person can meet the guidelines regarding physical activity and still be considered as sedentary if they spend a large amount of their day sitting or lying down at home, at school, at work, driving, or during their leisure time. It is therefore important to distinguish physical inactivity from sedentariness.
Defining what sedentariness is as a lifestyle would be complementary to the definition of sedentary behavior at any given moment. Furthermore, defining sedentariness as a lifestyle is an essential step in proposing recommendations when they are needed (as for physical activity), which could have a positive impact on the quality of life (i.e., physical, psychological, and social health and, hence, the overall health of an individual) (54). However, studying sedentariness is complex since several factors may influence the relationship between sedentary behavior and mental or physical health, such as the type of sedentary activities. For instance, strong evidence has been found regarding the association between cardiovascular diseases and TV viewing, total sitting time and screen time. However, evidence is weak for occupational sitting (25). Regarding psychological outcomes, cognitively demanding activities (e.g., sitting while reading, actively using a computer) are associated with better executive performances such as working memory (55, 56), mental flexibility (56) and visual spatial memory (55), while TV viewing is negatively associated with such executive performances among adults (55, 56). Moreover, physical activity and sedentariness might be two factors influencing each other in the long term (57–59). High levels of moderately intensive physical activity might attenuate the increased risk of death associated with high sitting times (57). Thus, when investigating sedentariness, the level of physical activity might also be considered. The same applies for age, since older individuals have been sedentary for longer periods of time than younger ones (60). A fourth factor to consider is the interruption of sedentary bouts. Health benefits have been demonstrated by breaking sedentary behavior every 20 (61, 62) or 30 min (6, 30, 63, 64). Yet, there is no consensus on the preferential frequency for breaking up sedentary time. Therefore, more studies are needed in order to gain a better understanding of the full scope of the consequences of sedentary behavior on health and at which point those consequences might be detrimental in the long term.
As mentioned earlier, thresholds would be useful in the definition of sedentariness as a lifestyle as it would allow sedentary individuals to be distinguished from non-sedentary ones. According to the Australian government (65), the cut-off point for mortality risk is approximately 7 or 8 h a day. Likewise, a meta-analysis on 6 studies among adults reported that sitting for more than 7 h a day is associated with an increased mortality risk (66). However, this meta-analysis disagrees with another which was (57) conducted on 13 studies and which revealed that sitting for more than 4 h a day is enough to increase the risk of all-cause mortality among adults. This inconsistency could be explained by the way in which sedentary behaviors are evaluated, as the evaluations were objective in some cases (e.g., with accelerometers), but subjective in others (questionnaires). However, questionnaires tend to underestimate total sedentary time (67, 68) compared to objective measures (18). This hypothesis was supported by a meta-regression analysis (69) which showed that the cut-off of daily sedentary time for self-reporting studies was 7 h/day compared with 9 h/day for device-based ones.
This lack of consensus has led researchers to use different criteria to define a sedentary lifestyle, making comparisons of the results difficult. A common definition of sedentariness would improve its study and the determination of the potentially detrimental consequences on the physiology, as well as other aspects that would impact the quality of life of individuals and their well-being. For example, sitting for less than 8 h a day is associated with higher perceived mental health and vitality scores (54) and lower anxiety (16, 54) and depression scores (13, 54).
Another example is the potential relationship between sedentary behavior and the increased risk of dementia (70), which currently lacks sufficient evidence (17). Recommendations for a sedentary lifestyle would enable the relationship between sitting time and an increased risk of dementia to be studied. If sedentariness is a risk factor for cognitive decline (18) and dementia (17, 70), then guidelines for sedentariness would grant the possibility of developing efficient intervention protocols in order to decrease sedentariness and make modern lifestyles healthier. Such interventions would reduce the high prevalence of dementia (71) and its economic cost (72). Therefore, a definition of sedentariness would provide a better understanding of this lifestyle and its physiological, psychological, economic and social implications. This definition should at least take into account the type of current and past sedentary activities (cognitively demanding vs. undemanding activities) and their duration, the type of current and past physical activity (low, moderate, vigorous), the way sedentarity is measured (objective measurements as far as possible), the interruption of sedentary bouts, and age.
VM reviewed the literature, created, and maintained a Zotero database, wrote the initial manuscript, and revised the second drafts following feedback from CA and FD. CA reviewed the literature. Both CA and FD made editorial suggestions for the second drafts. All authors contributed to manuscript revision, read and approved the submitted version.
Conflict of Interest Statement
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
1. Diaz KM, Howard VJ, Hutto B, Colabianchi N, Vena JE, Safford MM, et al. Patterns of sedentary behavior and mortality in U.S. middle-aged and older adults: a national cohort study. Ann Intern Med. (2017) 167:465–75. doi: 10.7326/M17-0212
2. Biswas A, Oh PI, Faulkner GE, Bajaj RR, Silver MA, Mitchell MS, et al. Sedentary time and its association with risk for disease incidence, mortality, and hospitalization in adults: a systematic review and meta-analysis. Ann Intern Med. (2015) 162:123–32. doi: 10.7326/M14-1651
3. Wilmot EG, Edwardson CL, Achana FA, Davies MJ, Gorely T, Gray LJ, et al. Sedentary time in adults and the association with diabetes, cardiovascular disease and death: systematic review and meta-analysis. Diabetologia (2012) 55:2895–905. doi: 10.1007/s00125-012-2677-z
4. Hamilton MT, Hamilton DG, Zderic TW. Role of low energy expenditure and sitting in obesity, metabolic syndrome, type 2 diabetes, and cardiovascular disease. Diabetes (2007) 56:2655–67. doi: 10.2337/db07-0882
6. Henson J, Dunstan DW, Davies MJ, Yates T. Sedentary behaviour as a new behavioural target in the prevention and treatment of type 2 diabetes. Diabetes Metab Res Rev. (2016) 32 (Suppl. 1):213–20. doi: 10.1002/dmrr.2759
7. Dunstan DW, Barr ELM, Healy GN, Salmon J, Shaw JE, Balkau B, et al. Television viewing time and mortality: the Australian diabetes, obesity and lifestyle study (AusDiab). Circulation (2010) 121:384–91. doi: 10.1161/CIRCULATIONAHA.109.894824
10. Daneshmandi H, Choobineh A, Ghaem H, Karimi M. Adverse effects of prolonged sitting behavior on the general health of office workers. J Lifestyle Med. (2017) 7:69–75. doi: 10.15280/jlm.2017.7.2.69
11. Sharan D, Rajkumar JS, Balakrishnan R. 644 Risk factors for work related musculoskeletal disorders among physiotherapists. Occup Environ Med. (2018) 75:A183–4. doi: 10.1136/oemed-2018-ICOHabstracts.518
12. Blough J, Loprinzi PD. Experimentally investigating the joint effects of physical activity and sedentary behavior on depression and anxiety: a randomized controlled trial. J Affect Disord. (2018) 239:258–68. doi: 10.1016/j.jad.2018.07.019
13. Stubbs B, Vancampfort D, Firth J, Schuch FB, Hallgren M, Smith L, et al. Relationship between sedentary behavior and depression: a mediation analysis of influential factors across the lifespan among 42,469 people in low- and middle-income countries. J Affect Disord. (2018) 229:231–8. doi: 10.1016/j.jad.2017.12.104
15. Edwards MK, Loprinzi PD. Experimentally increasing sedentary behavior results in increased anxiety in an active young adult population. J Affect Disord. (2016) 204:166–73. doi: 10.1016/j.jad.2016.06.045
16. Vancampfort D, Stubbs B, Herring MP, Hallgren M, Koyanagi A. Sedentary behavior and anxiety: association and influential factors among 42,469 community-dwelling adults in six low- and middle-income countries. Gen Hosp Psychiatry (2018) 50:26–32. doi: 10.1016/j.genhosppsych.2017.09.006
17. Falck RS, Davis JC, Liu-Ambrose T. What is the association between sedentary behaviour and cognitive function? A systematic review. Br J Sports Med. (2017) 51:800–11. doi: 10.1136/bjsports-2015-095551
18. Ku P-W, Liu Y-T, Lo M-K, Chen L-J, Stubbs B. Higher levels of objectively measured sedentary behavior is associated with worse cognitive ability: two-year follow-up study in community-dwelling older adults. Exp Gerontol. (2017) 99:110–14. doi: 10.1016/j.exger.2017.09.014
19. Vancampfort D, Stubbs B, Lara E, Vandenbulcke M, Swinnen N, Smith L, et al. Mild cognitive impairment and sedentary behavior: a multinational study. Exp Gerontol. (2018) 108:174–80. doi: 10.1016/j.exger.2018.04.017
21. Herber-Gast G-CM, Jackson CA, Mishra GD, Brown WJ. Self-reported sitting time is not associated with incidence of cardiovascular disease in a population-based cohort of mid-aged women. Int J Behav Nutr Phys Act. (2013) 10:55. doi: 10.1186/1479-5868-10-55
22. Stamatakis E, Pulsford RM, Brunner EJ, Britton AR, Bauman AE, Biddle SJ, et al. Sitting behaviour is not associated with incident diabetes over 13 years: The whitehall II cohort study. Br J Sports Med. (2017) 51:818–23. doi: 10.1136/bjsports-2016-096723
26. Salmon J, Owen N, Crawford D, Bauman A, Sallis JF. Physical activity and sedentary behavior: a population-based study of barriers, enjoyment, and preference. Health Psychol. (2003) 22:178–88. doi: 10.1037/0278-622.214.171.124
29. Henson J, Davies MJ, Bodicoat DH, Edwardson CL, Gill JMR, Stensel DJ, Tolfrey K, et al. Breaking up prolonged sitting with standing or walking attenuates the postprandial metabolic response in postmenopausal women: a randomized acute study. Diabetes Care (2016) 39:130–8. doi: 10.2337/dc15-1240
30. Thorp AA, Kingwell BA, Sethi P, Hammond L, Owen N, Dunstan DW. Alternating bouts of sitting and standing attenuate postprandial glucose responses. Med Sci Sports Exerc. (2014) 46:2053–61. doi: 10.1249/MSS.0000000000000337
31. Duvivier BMFM, Schaper NC, Hesselink MKC, van Kan L, Stienen N, Winkens B, et al. Breaking sitting with light activities vs. structured exercise: A randomised crossover study demonstrating benefits for glycaemic control and insulin sensitivity in type 2 diabetes. Diabetologia (2017) 60:490–8. doi: 10.1007/s00125-016-4161-7
32. Bailey DP, Locke CD. Breaking up prolonged sitting with light-intensity walking improves postprandial glycemia, but breaking up sitting with standing does not. J Sci Med Sport (2015) 18:294–8. doi: 10.1016/j.jsams.2014.03.008
34. Hawari NSA, Al-Shayji I, Wilson J, Gill JMR. Frequency of breaks in sedentary time and postprandial metabolic responses. Med Sci Sports Exerc. (2016) 48:2495–502. doi: 10.1249/MSS.0000000000001034
35. Tremblay MS, Aubert S, Barnes JD, Saunders TJ, Carson V, Latimer-Cheung AE, et al. Sedentary behavior research network (SBRN) – Terminology consensus project process and outcome. Int J Behav Nutr Phys Act. (2017) 14:75. doi: 10.1186/s12966-017-0525-8
36. World Health Organization. Global Recommendations on Physical Activity for Health. (2010) Available at: http://www.who.int/dietphysicalactivity/factsheet_recommendations/en/
37. Hallal PC, Andersen LB, Bull FC, Guthold R, Haskell W, Ekelund U. Global physical activity levels: Surveillance progress, pitfalls, and prospects. Lancet (2012) 380:247–57. doi: 10.1016/S0140-6736(12)60646-1
38. Keadle SK, McKinnon R, Graubard BI, Troiano RP. Prevalence and trends in physical activity among older adults in the United States: a comparison across three national surveys. Prev Med. (2016) 89:37–43. doi: 10.1016/j.ypmed.2016.05.009
39. Sullivan PW, Morrato EH, Ghushchyan V, Wyatt HR, Hill JO. Obesity, inactivity, and the prevalence of diabetes and diabetes-related cardiovascular comorbidities in the U.S., 2000-2002. Diabetes Care (2005) 28:1599–603. doi: 10.2337/diacare.28.7.1599
40. Admiraal WM, van Valkengoed IGM, L de Munter JS, Stronks K, Hoekstra JBL, Holleman F. The association of physical inactivity with Type 2 diabetes among different ethnic groups. Diabet Med J Br Diabet Assoc. (2011) 28:668–72. doi: 10.1111/j.1464-5491.2011.03248.x
41. Longo-Mbenza B, On'kin JBKL, Okwe AN, Kabangu NK, Fuele SM. Metabolic syndrome, aging, physical inactivity, and incidence of type 2 diabetes in general African population. Diab Vasc Dis Res. (2010) 7:28–39. doi: 10.1177/1479164109346362
42. Lee I-M, Shiroma EJ, Lobelo F, Puska P, Blair SN, Katzmarzyk PT. Effect of physical inactivity on major non-communicable diseases worldwide: an analysis of burden of disease and life expectancy. Lancet (2012) 380:219–29. doi: 10.1016/S0140-6736(12)61031-9
44. Wen CP, Wai JPM, Tsai MK, Yang YC, Cheng TYD, Lee M-C, et al. Minimum amount of physical activity for reduced mortality and extended life expectancy: a prospective cohort study. Lancet (2011) 378:1244–53. doi: 10.1016/S0140-6736(11)60749-6
45. Harris MA. The relationship between physical inactivity and mental wellbeing: findings from a gamification-based community-wide physical activity intervention. Health Psychol Open (2018) 5:2055102917753853. doi: 10.1177/2055102917753853
46. Wu X, Tao S, Zhang Y, Zhang S, Tao F. Low physical activity and high screen time can increase the risks of mental health problems and poor sleep quality among Chinese college students. PLoS ONE (2015) 10:e0119607. doi: 10.1371/journal.pone.0119607
48. Ding D, Lawson KD, Kolbe-Alexander TL, Finkelstein EA, Katzmarzyk PT, van Mechelen W, et al. The economic burden of physical inactivity: a global analysis of major non-communicable diseases. Lancet (2016) 388:1311–24. doi: 10.1016/S0140-6736(16)30383-X
51. León-Muñoz LM, Martínez-Gómez D, Balboa-Castillo T, López-García E, Guallar-Castillón P, Rodríguez-Artalejo F. Continued sedentariness, change in sitting time, and mortality in older adults. Med Sci Sports Exerc. (2013) 45:1501–7. doi: 10.1249/MSS.0b013e3182897e87
52. Rezende LF, Sá TH, Mielke GI, Viscondi JYK, Rey-López JP, Garcia LMT. All-cause mortality attributable to sitting time: Analysis of 54 countries worldwide. Am J Prev Med. (2016) 51:253–263. doi: 10.1016/j.amepre.2016.01.022
53. van der Ploeg HP, Chey T, Korda RJ, Banks E, Bauman A. Sitting time and all-cause mortality risk in 222 497 Australian adults. Arch Intern Med. (2012) 172:494–500. doi: 10.1001/archinternmed.2011.2174
54. Gibson A-M, Muggeridge DJ, Hughes AR, Kelly L, Kirk A. An examination of objectively-measured sedentary behavior and mental well-being in adults across week days and weekends. PLoS ONE (2017) 12:e0185143. doi: 10.1371/journal.pone.0185143
55. Bakrania K, Edwardson CL, Khunti K, Bandelow S, Davies MJ, Yates T. Associations between sedentary behaviors and cognitive function: cross-sectional and prospective findings from the UK biobank. Am J Epidemiol. (2018) 187:441–54. doi: 10.1093/aje/kwx273
56. Kesse-Guyo E, Charreire H, Andreeva VA, Touvier M, Hercberg S, Galan P, et al. Cross-sectional and longitudinal associations of different sedentary behaviors with cognitive performance in older adults. PLoS ONE (2012) 7:e47831. doi: 10.1371/journal.pone.0047831
57. Ekelund U, Steene-Johannessen J, Brown WJ, Fagerland MW, Owen N, Powell KE, 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. Lancet (2016) 388:1302–10. doi: 10.1016/S0140-6736(16)30370-1
58. Petersen CB, Bauman A, Grønbæk M, Wulff Helge J, Thygesen LC, Tolstrup JS. Total sitting time and risk of myocardial infarction, coronary heart disease and all-cause mortality in a prospective cohort of Danish adults. Int J Behav Nutr Phys Act. (2014) 11:13. doi: 10.1186/1479-5868-11-13
59. Petersen CB, Bauman A, Tolstrup JS. Total sitting time and the risk of incident diabetes in Danish adults (the DANHES cohort) over 5 years: a prospective study. Br J Sports Med. (2016) 50:1382–7. doi: 10.1136/bjsports-2015-095648
61. Larsen RN, Dempsey PC, Dillon F, Grace M, Kingwell BA, Owen N, et al. Does the type of activity “break” from prolonged sitting differentially impact on postprandial blood glucose reductions? An exploratory analysis. Appl Physiol Nutr Metab. (2017) 42:897–900. doi: 10.1139/apnm-2016-0642
62. Dunstan DW, Kingwell BA, Larsen R, Healy GN, Cerin E, Hamilton MT, et al. Breaking up prolonged sitting reduces postprandial glucose and insulin responses. Diabetes Care (2012) 35:976–83. doi: 10.2337/dc11-1931
63. Thorp AA, Kingwell BA, Owen N, Dunstan DW. Breaking up workplace sitting time with intermittent standing bouts improves fatigue and musculoskeletal discomfort in overweight/obese office workers. Occup Environ Med. (2014) 71:765–71. doi: 10.1136/oemed-2014-102348
64. Wennberg P, Boraxbekk C-J, Wheeler M, Howard B, Dempsey PC, Lambert G, et al. Acute effects of breaking up prolonged sitting on fatigue and cognition: a pilot study. BMJ Open (2016) 6:e009630. doi: 10.1136/bmjopen-2015-009630
67. Copeland JL, Ashe MC, Biddle SJ, Brown WJ, Buman MP, Chastin S, et al. Sedentary time in older adults: a critical review of measurement, associations with health, and interventions. Br J Sports Med. (2017) 51:1539. doi: 10.1136/bjsports-2016-097210
69. Ku P-W, Steptoe A, Liao Y, Hsueh M-C, Chen L-J. A cut-off of daily sedentary time and all-cause mortality in adults: a meta-regression analysis involving more than 1 million participants. BMC Med. (2018) 16:74. doi: 10.1186/s12916-018-1062-2
70. Wheeler MJ, Dempsey PC, Grace MS, Ellis KA, Gardiner PA, Green DJ, et al Sedentary behavior as a risk factor for cognitive decline? A focus on the influence of glycemic control in brain health. Alzheimers Dement Transl Res Clin Interv. (2017) 3:291–300. doi: 10.1016/j.trci.2017.04.001
71. Prince M, Bryce R, Albanese E, Wimo A, Ribeiro W, Ferri CP. The global prevalence of dementia: A systematic review and metaanalysis. Alzheimers Dement J Alzheimers Assoc. (2013) 9:63–75.e2. doi: 10.1016/j.jalz.2012.11.007
Keywords: sedentariness, sedentary behavior, health, sitting, standing, physical activity
Citation: Magnon V, Dutheil F and Auxiette C (2018) Sedentariness: A Need for a Definition. Front. Public Health 6:372. doi: 10.3389/fpubh.2018.00372
Received: 06 July 2018; Accepted: 04 December 2018;
Published: 21 December 2018.
Edited by:Daniel P. Bailey, University of Bedfordshire Bedford, United Kingdom
Reviewed by:Céline Aguer, Institut du Savoir Montfort (ISM), Canada
Copyright © 2018 Magnon, Dutheil and Auxiette. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Catherine Auxiette, email@example.com