Epidemiology of sedentary behaviour in office workers Dr Stacy Clemes Physical Activity and Public Health Research Group School of Sport, Exercise & Health Sciences, Loughborough University S.A.Clemes@lboro.ac.uk
Sedentary behaviour What is Sedentary Behaviour? any waking behaviour characterised by an energy expenditure 1.5 METs while in a sitting or reclining posture. (Sedentary Behaviour Research Network, 2012, page 540)
What is Sedentary Behaviour? From Hamilton et al. 2007, Diabetes What is Sedentary Behaviour?
The convenience of our lifestyles Motorised transport Physical activity Built environment Elevators Escalators Workplace Labour-saving devices in the work environment Computers Electronically powered tools and gadgets Sitting Home, leisure Television Video games Computers Domestic labour-saving devices
The convenience of our lifestyles
Changes to the workplace
The modern day office - too comfortable?
08:31 08:51 09:11 09:31 09:51 10:11 10:31 10:51 11:11 11:31 11:51 12:11 12:31 12:51 13:11 13:31 13:51 14:11 14:31 14:51 15:11 15:31 15:51 16:11 16:31 16:51 17:11 17:31 17:51 18:11 18:31 18:51 19:11 19:31 19:51 20:11 20:31 20:51 21:11 21:31 21:51 22:11 Activity counts (CPM) A typical day in the office. 16000 14000 12000 10000 Time spent active and sedentary Light activity 75 minutes Moderate activity 24 minutes Vigorous activity 14 minutes Sedentary 647 minutes 8000 6000 4000 2000 0 Time
Sedentary Behaviour Prevalence Sedentary behaviour is the most prevalent behaviour seen throughout waking hours >50% of total daily sitting time occurs at work (Miller and Brown, 2004)
Sedentary Behaviour and Health Sitting time and all-cause mortality (Katzmarzyk et al., 2009) Data from 17,013 Canadians, followed-up for 12 years
Sedentary Behaviour and Health TV viewing and cardiovascular disease mortality (Matthews et al., 2012) Data from 240,819 US adults, followed-up for 8.5 years
Sedentary Behaviour and Health Sitting time and associations with diabetes, cardiovascular disease and death: Systematic review and meta-analysis (Wilmot et al., 2012) 18 studies included in review, 794,577 participants The greatest sedentary time compared with the lowest was associated with: 112% increase risk of developing diabetes 147% increase risk of suffering a cardiovascular event 90% increase risk of cardiovascular mortality 49% increase risk of all-cause mortality
Sedentary Behaviour and Health Sedentary Behaviour and Cancer: A Systematic Review (Lynch et al., 2010) Significant, positive associations between sedentary behaviour (highest levels vs lowest) and cancer found in 8 out of 11 studies : 78% increase risk of colorectal cancer 66% increase risk of ovarian cancer 39% increase risk of prostate cancer 34% increase risk of endometrial cancer Further evidence in needed linking sedentary behaviour and cancer
Sedentary Behaviour and Health Breaking up Sedentary Behaviour (image from Owen et al., 2010)
Sedentary Behaviour and Health Breaking up Sedentary Behaviour Regular breaks in sedentary time are associated with cardiometabolic health benefits (Healy et al., 2008, 2011; Carson et al., 2014) Data from 4,935 Canadian adults (Carson et al. 2014) have shown that increased number of breaks in sedentary time are associated with: lower waist circumference lower systolic blood pressure higher HDL-cholesterol levels lower blood triglycerides levels lower blood glucose levels lower blood insulin levels
Sedentary Behaviour and Health Breaking up Sedentary Behaviour Laboratory evidence - breaking up sitting every 20 minutes with light or moderate activity has beneficial effects on blood glucose and insulin (Dunstan et al. 2012)
Sedentary Behaviour and Health Breaking up Sedentary Behaviour putting research into practice
Measurement of Sedentary Behaviour Self-report measures Early studies focussed on TV viewing Single-item measures (e.g. International Physical Activity Questionnaire) Domain-specific sitting (e.g. Marshall et al. 2010)
Objective measures Measurement of Sedentary Behaviour Accelerometers estimate sedentary time through a lack of movement Inclinometers the activpal, directly measures sitting, standing and walking The Sitting Pad directly measures sitting (image from Ryde et al. 2012)
Prevalence of Sedentary Behaviour US adults (n = 4,632) accelerometer data from the 2003 2004 National Health and Nutrition Examination Survey (NHANES) Adults spent 7.7 hours/day sedentary (55% of waking hours) (Matthews et al. 2007) Canadian adults (n = 2,832) - accelerometer data from the 2007-2009 Canadian Health Measures Survey (CHMS). Adults spent 9.5 hours/day sedentary (69% of waking hours) (Colley et al. 2011) UK adults (n = 2,338) - accelerometer data from the 2008 Health Survey for England. Adults spent 9.8 hours/day sedentary (Craig et al. 2009)
Sitting time (minutes) Sitting time across the segmented work day in 72 office workers 500 400 Workday sitting: ~8 hrs/day 300 Non-workday sitting: ~5 hrs, 40 mins/day 200 65% of time at work was reportedly spent sitting 100 Sitting at work accounted for 63% of total sitting time 0 Mon Tue Wed Thu Fri Sat Sun Evening sitting time Afternoon sitting time Morning sitting time Mean time at work: 8 hrs 26 mins Clemes et al. 2014, Occup Med
Time (minutes) Time spent sedentary and in physical activity in 172 office workers 1000 900 800 700 600 500 400 300 200 100 32 mins 4% ~4 hrs 28% ~4.5 hrs 9 hrs 40 68% 28 mins 4% 36% 7 hrs 40 60% MVPA LPA SB 0 Workdays Non-Workdays Median wear time: weekdays 858±103 mins (~14 hrs); weekend days 766±113 mins (~13 hrs)
Mean minutes spent in each behaviour (mins/hr) Hourly patterns of sedentary behaviour, light activity & MVPA - Workdays 60 50 40 30 20 71% of time at work was spent sedentary Sedentary time at work accounted for 57% of total daily sedentary time Sedentary Light activity MVPA 10 0 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Hour Clemes et al. 2014, J Occup Environ Med
Mean minutes spent in each behaviour (mins/hr) Hourly patterns of sedentary behaviour, light activity & MVPA - Weekends 60 50 40 30 Sedentary Light activity MVPA 20 10 0 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Hour Clemes et al. 2014, J Occup Environ Med
Time spent sedentary and in physical activity in 172 office workers Participants grouped into tertiles based on sedentary time at work High work sitters spent a higher proportion of time in sedentary behaviour, and a lower proportion of time in light activity after work and on weekend days (p<0.05) No differences between groups in the proportion of time in MVPA after work and on weekend days (p>0.05)
Minutes Sedentary behaviour in 4436 office workers: The Stormont Study 700 600 500 400 Sitting time at work accounted for 60% of total daily sitting 300 time 200 Leisure time Using PC at home Watching TV At work Travelling 100 0 Work day Non work day N = 4,436 (56% female, age: 44.2±10 yrs, BMI: 27.2±5 kg/m 2 ) Clemes et al. submitted
Descriptive epidemiology of sitting times Sociodemographic characteristics Workday sitting Non-workday sitting Sex No significant difference Males > females Age BMI Sedentary behaviour in 4436 office workers: The Stormont Study 18 29 year olds > all other groups Obese > normal weight & overweight 18 29 year olds > all other groups Obese > normal weight & overweight Education No significant difference School level > all other groups Martial status Work pattern Single/divorced/widowed > married/co-habiting Full time workers > part time workers Single/divorced/widowed > married/co-habiting Full time workers > part time workers
Key findings Office workers spend a high proportion of time in sedentary behaviours, during and outside work (totalling 9-10 hrs/day) The workplace contributes to high volumes of sedentary behaviour Those who are most sedentary at work tend to be most sedentary outside of work These individuals do not compensate for sedentary behaviour at work by being more active in their leisure time
Current work: implementing an improved working environment Tips to reduce sitting at work: Standing meetings Walking meetings Stand to talk on the phone Height adjustable desks Use of a pooled printer
Current work: targeting the next generation of workers
An improved working environment this is not a new concept Many successful individuals/businesses have implemented walking meetings and standing at work. Steve Jobs, the late founder of Apple, Facebook's Mark Zuckerberg and Jack Dorsey of Twitter have all been known to favour walking meetings Adrian Newey, most successful F1 designer, stands at his drawing board
Thank you for listening! For further information, see: http://www.bbc.co.uk/news/health-27305330 BBC Feature Sitting while working can increase risk of diabetes