title: Randomized controlled pilot of an intervention to reduce and break-up overweight/obese adults' overall sitting-time.
abstract: BACKGROUND
  Too much prolonged sitting is a prevalent health risk among adults. Interventions have focused mainly on the workplace, with limited attention to non-work settings. The effectiveness of a short-term intervention to reduce and break-up sitting-time in overweight/obese adults was examined. This pilot study sought to determine the feasibility of interrupting sitting to stand/ambulate objectively with ActivPAL devices which provide a valid measurement of sit/stand transitions.
  
  
  METHODS
  This is a cross-over randomized controlled pilot that included 10 participants (aged 37-65 years) and although a small and short-term intervention (1-week intervention; no washout) further informs on the feasibility of interventions on a larger scale. At the workplace, screen-delivered hourly alerts prompted participants to break-up sitting-time through adopting walking behaviors (approximately 30-60 minutes day(-1)). During transportation/home/leisure-time individual goals for steps day(-1) were set and sitting-reduction strategies (including behavioral self-monitoring) were delivered through daily text messages. Change in inclinometer-derived sitting-time is the main outcome. Standing, stepping, number of sit/stand transitions and participant satisfaction were also examined.
  
  
  RESULTS
  For the intervention compared to the control-week (mean difference (95 % confidence interval); p value), participants had less sitting-time (1.85 hours (0.96-2.75); p = 0.001), more standing (0.77 hours (0.06-1.48); p = 0.036), and more stepping (1.09 hours (0.79- 1.38); p < 0.001). Importantly, there was no change in the total number of sit/stand transitions (3.28 (-2.33-8.89); p = 0.218) despite successfully reducing sitting-time and increasing time spent standing and walking.
  
  
  CONCLUSIONS
  Sitting-time in overweight/obese adults can be reduced following a brief multi-component intervention based on prompts, telephone support, goal setting and behavioral self-monitoring. However, the results from this pilot study provide new insight that when overweight/obese adults attempted to reduce sedentary-time by walking and standing for approximately 2 hour day(-1) more than usual, they did not actually get up from sitting more often (i.e. increasing the number of sit/stand transitions), but instead remained on their feet for longer during each non-sitting bout. This behavioral resistance to make more sit/stand transitions (i.e. get-up from sitting more often) may have important implications for future modification programs and supports the concept that when overweight/obese people are sitting, people seem to prefer not to interrupt the sedentary behavior to get-up from sitting.
  
  
  BACKGROUND
  26 November 2013, ClinicalTrials.govID: NCT02007681 (first participant was randomized on 2 September 2013).
authors.affiliation: Universidade de Lisboa, Exercise and Health Laboratory, Interdisciplinary Center for the Study of Human Performance, Faculdade de Motricidade Humana, Estrada da Costa, 1499-002, Cruz-Quebrada, Portugal. pedrojudice@fmh.ulisboa.pt.
authors.forename: Pedro B
authors.initials: PB
authors.lastname: Júdice
authors.affiliation: Texas Obesity Research Center, Houston, TX, USA. mhamilton7@uh.edu.
authors.forename: Marc T
authors.initials: MT
authors.lastname: Hamilton
authors.affiliation: Universidade de Lisboa, Exercise and Health Laboratory, Interdisciplinary Center for the Study of Human Performance, Faculdade de Motricidade Humana, Estrada da Costa, 1499-002, Cruz-Quebrada, Portugal. lsardinha@fmh.ulisboa.pt.
authors.forename: Luís B
authors.initials: LB
authors.lastname: Sardinha
authors.affiliation: Universidade de Lisboa, Exercise and Health Laboratory, Interdisciplinary Center for the Study of Human Performance, Faculdade de Motricidade Humana, Estrada da Costa, 1499-002, Cruz-Quebrada, Portugal. analiza@fmh.ulisboa.pt.
authors.forename: Analiza M
authors.initials: AM
authors.lastname: Silva
mesh_terms: D056044:Actigraphy / Q000295:instrumentation; D000328:Adult; D000368:Aged; D018592:Cross-Over Studies; D005240:Feasibility Studies; D005260:Female; D006040:Goals; D015438:Health Behavior; D006304:Health Status; D006801:Humans; D007899:Leisure Activities; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009765:Obesity / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D016272:Occupational Health; D050177:Overweight / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D010865:Pilot Projects; D011174:Portugal; D017010:Reminder Systems; D040242:Risk Reduction Behavior; D057185:Sedentary Behavior; D012648:Self Care; D013689:Telephone; D060145:Text Messaging; D013997:Time Factors; D016138:Walking; D017132:Workplace