Background. The link between physical activity and health outcomes is well established, yet levels of physical activity remain low. This study quantifies effects on mortality of the substitution of low activity episodes by higher activity alternatives using time-use data. Methods. Sample time profiles are representative of the Canadian population ( ). Activity time and mortality are linked using metabolic equivalents(METs). Mortality risk is determined by peak daily METs and hours spent sedentary. The impact of altering activity patterns is assessed using simulated life expectancy. Results. If all leisure screen time was replaced with an equal amount of time spent going for a walk, an increase in life expectancy of about 2.5 years (95% CI, 1.4 to 3.8) would be expected. No other activity category would have as large as an effect. Conclusions. Reducing leisure screen time has a large effect, because seniors particularly have a large potential for mortality reduction and watch more television than other age groups. The general problem of inactivity cannot be solved simply by reallocating time to more active pursuits, because daily activity patterns can be heterogeneous or fragmented and activities may be nondiscretionary (e.g., work or childcare). 1. Introduction The positive relationship between physical activity and health is well established [1–5], yet levels of physical activity and fitness remain low [6–9], while obesity rates are high, [9, 10] collectively threatening the persistent increase in life expectancy enjoyed over the past century [11]. Physical activity is associated with a decreased risk of mortality, cardiovascular disease, diabetes, colon cancer, osteoporosis, depression, and other chronic disease conditions [1–5], making it an important health promoting behaviour and a priority for intervention. Accumulating evidence shows that sedentary behaviours, independent of physical activity levels, are associated with increased risk of cardiometabolic disease, all-cause mortality, and a variety of physiological and psychological problems [12–17]. Therefore, to maximize health benefits, approaches to resolve the inactivity crisis should attempt to both increase deliberate physical activity and decrease sedentary behaviours. Physical inactivity is pervasive, persistent, and a challenge to overcome. It is generally believed that a multilevel, multisectoral approach is required to increase population levels of physical activity [18]. Ultimately, resolving the problem of inactivity requires a sustained change in individual daily activity patterns.
References
[1]
United States Department of Health and Human Services, “Physical activity and health: a report of the surgeon general,” Tech. Rep., United States Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Atlanta, Ga, USA, 1996.
[2]
Physical Activity Guidelines Advisory Committee, “Physical activity guidelines advisory committee report,” Tech. Rep., United States Department of Health and Human Services, Washington, DC, USA, 2008.
[3]
I. Janssen and A. G. LeBlanc, “Systematic review of the health benefits of physical activity and fitness in school-aged children and youth,” International Journal of Behavioral Nutrition and Physical Activity, vol. 7, article 40, 2010.
[4]
D. E. R. Warburton, S. Charlesworth, A. Ivey, L. Nettlefold, and S. S. D. Bredin, “A systematic review of the evidence for Canada's Physical Activity Guidelines for Adults,” International Journal of Behavioral Nutrition and Physical Activity, vol. 7, article 39, 2010.
[5]
D. H. Paterson and D. E. R. Warburton, “Physical activity and functional limitations in older adults: a systematic review related to Canada's Physical Activity Guidelines,” International Journal of Behavioral Nutrition and Physical Activity, vol. 7, article no. 38, 2010.
[6]
R. P. Troiano, D. Berrigan, K. W. Dodd, L. C. Masse, T. Tilert, and M. Mcdowell, “Physical activity in the United States measured by accelerometer,” Medicine and Science in Sports and Exercise, vol. 40, no. 1, pp. 181–188, 2008.
[7]
P. T. Katzmarzyk and M. S. Tremblay, “Limitations of Canada's physical activity data: implications for monitoring trends,” Applied Physiology, Nutrition and Metabolism, vol. 32, pp. S185–S194, 2007.
[8]
M. S. Tremblay, M. Shields, M. Laviolette, C. L. Craig, I. Janssen, and S. C. Gorber, “Fitness of Canadian children and youth: results from the 2007–2009 Canadian Health Measures Survey,” Health Reports, vol. 21, no. 1, pp. 7–20, 2010.
[9]
M. Shields, M. S. Tremblay, M. Laviolette, C. L. Craig, I. Janssen, and S. C. Gorber, “Fitness of Canadian adults: results from the 2007–2009 Canadian Health Measures Survey,” Health Reports, vol. 21, no. 1, pp. 21–35, 2010.
[10]
K. M. Flegal, M. D. Carroll, C. L. Ogden, and L. R. Curtin, “Prevalence and trends in obesity among US adults, 1999–2008,” The Journal of the American Medical Association, vol. 303, no. 3, pp. 235–241, 2010.
[11]
S. J. Olshansky, D. J. Passaro, R. C. Hershow et al., “A potential decline in life expectancy in the United States in the 21st century,” The New England Journal of Medicine, vol. 352, no. 11, pp. 1138–1145, 2005.
[12]
P. T. Katzmarzyk, T. S. Church, C. L. Craig, and C. Bouchard, “Sitting time and mortality from all causes, cardiovascular disease, and cancer,” Medicine and Science in Sports and Exercise, vol. 41, no. 5, pp. 998–1005, 2009.
[13]
N. Owen, A. Bauman, and W. Brown, “Too much sitting: a novel and important predictor of chronic disease risk?” British Journal of Sports Medicine, vol. 43, no. 2, pp. 81–83, 2009.
[14]
M. S. Tremblay, R. C. Colley, T. J. Saunders, G. N. Healy, and N. Owen, “Physiological and health implications of a sedentary lifestyle,” Physiology, Nutrition and Metabolism, vol. 35, no. 6, pp. 725–740, 2010.
[15]
A. V. Patel, L. Bernstein, A. Deka et al., “Leisure time spent sitting in relation to total mortality in a prospective cohort of US adults,” American Journal of Epidemiology, vol. 172, no. 4, pp. 419–429, 2010.
[16]
D. W. Dunstan, E. L. M. Barr, J. E. Shaw et al., “Response to letters regarding article, ‘television viewing time and mortality: the Australian diabetes, obesity and lifestyle study (AusDiab)’,” Circulation, vol. 122, no. 13, p. e472, 2010.
[17]
M. Inoue, H. Iso, S. Yamamoto et al., “Daily total activity level and premature death in men and women: results from a large-scale population-based cohort study in Japan (JPHC Study),” Annals of Epidemiology, vol. 18, no. 7, pp. 522–530, 2008.
A. E. Bauman, J. F. Sallis, D. A. Dzewaltowski, and N. Owen, “Toward a better understanding of the influences on physical activity: the role of determinants, correlates, causal variables, mediators, moderators, and confounders,” American Journal of Preventive Medicine, vol. 23, no. 2, supplement 1, pp. 5–14, 2002.
[20]
C. Bouchard and P. T. Katzmarzyk, Eds., Physical Activity and Obesity, Pennington Biomedical Research Centre, Baton Rouge, La, USA, 2010.
[21]
M. John and S. A. Robert, “No time to lose? Time constraints and physical activity,” Working Paper 14513, National Bureau of Economic Research, 2008.
[22]
K. Y. Wolin, G. G. Bennett, L. H. McNeill, G. Sorensen, and K. M. Emmons, “Low discretionary time as a barrier to physical activity and intervention uptake,” American Journal of Health Behavior, vol. 32, no. 6, pp. 563–569, 2008.
[23]
Transportation Research Board, “Does the built environment influence physical activity? Examining the evidence,” TRB Special Report 282, Committee on Physical Activity, Health, Transportation, and Land Use, Transportation Research Board and Institute of Medicine of the National Academies of Science, 2005.
[24]
A. A. Lake, T. G. Townshend, and S. Alvanides, Eds., Obesegenic Environments: Complexities, Perceptions and Objective Measures, Wiley-Blackwell, Oxford, UK, 2010.
[25]
K. L. Edwards and G. P. Clarke, “The design and validation of a spatial microsimulation model of obesogenic environments for children in Leeds, UK: SimObesity,” Social Science and Medicine, vol. 69, no. 7, pp. 1127–1134, 2009.
[26]
Statistics Canada, “Overview of the time use of Canadians,” General Social Survey on Time Use 12F0080XIE, 2005.
[27]
Statistics Canada, “General Social Survey—Time Use, Detailed information for 2005 (Cycle 19) and Data Files,” http://www.statcan.gc.ca/cgibin/imdb/p2SV.pl?Function=getSurvey&SurvId=4503&SurvVer=2&InstaId=16848&InstaVer=4&SDDS=4503&lang=en&db=IMDB&adm=8&dis=2.
[28]
B. Lenz and C. Nobis, “The changing allocation of activities in space and time by the use of ICT—“Fragmentation” as a new concept and empirical results,” Transportation Research A, vol. 41, no. 2, pp. 190–204, 2007.
[29]
C. H. Wen and F. S. Koppelman, “A conceptual and methdological framework for the generation of activity-travel patterns,” Transportation, vol. 27, no. 1, pp. 5–23, 2000.
[30]
D. S. Hamermesh and S. Donald, “The time and timing costs of market work,” Working Paper number 13127, National Bureau of Economic Research, 2007.
[31]
B. E. Ainsworth, W. L. Haskell, M. C. Whitt et al., “Compendium of physical activities: an update of activity codes and MET intensities,” Medicine and Science in Sports and Exercise, vol. 32, no. 9, pp. S498–S504, 2000.
[32]
C. Tudor-Locke, T. L. Washington, B. E. Ainsworth, and R. P. Troiano, “Linking the American Time Use Survey (ATUS) and the compendium of physical activities: methods and rationale,” Journal of Physical Activity and Health, vol. 6, no. 3, pp. 347–353, 2009.
[33]
S. A. Prince, K. B. Adamo, M. E. Hamel, J. Hardt, S. Connor Gorber, and M. Tremblay, “A comparison of direct versus self-report measures for assessing physical activity in adults: a systematic review,” International Journal of Behavioral Nutrition and Physical Activity, vol. 5, article no. 55, 2008.
[34]
M. J. Greenacre, Theory and Applications of Correspondence Analysis, Academic Press, London, UK, 1984.
[35]
M. F. Leitzmann, Y. Park, A. Blair et al., “Physical activity recommendations and decreased risk of mortality,” Archives of Internal Medicine, vol. 167, no. 22, pp. 2453–2460, 2007.
[36]
“Statistics Canada: Life Tables, Canada, Provinces and Territories: 2000 to 2002,” http://www5.statcan.gc.ca/access_acces/archive.action?loc=/pub/84-537-x/2006001/4227757-eng.pdf.
[37]
“Statistics Canada: Canadian vital statistics data,” http://www5.statcan.gc.ca/cansim/directory-repertoire?lang=eng&groupid=051.
[38]
D. ？s, “Studies of time-use: problems and prospects,” Acta Sociologica, vol. 21, no. 2, pp. 125–141, 1978.
[39]
S. T. Stewart, D. M. Cutler, and A. B. Rosen, “Forecasting the effects of obesity and smoking on U.S. life expectancy,” The New England Journal of Medicine, vol. 361, no. 23, pp. 2252–2260, 2009.
