title: How does a hilly urban environment influence daily physical activity in obese individuals?
abstract: BACKGROUND
  Increases in physical activity (PA) are promoted by walking in an outdoor environment. Along with walking speed, slope is a major determinant of exercise intensity, and energy expenditure. The hypothesis was that in free-living conditions, a hilly environment diminishes PA to a greater extent in obese (OB) when compared with control (CO) individuals.
  
  
  METHODS
  To assess PA types and patterns, 28 CO (22 ± 2 kg/m²) and 14 OB (33 ± 4 kg/m²) individuals wore during an entire day 2 accelerometers and 1 GPS device, around respectively their waist, ankle and shoulder. They performed their usual PA and were asked to walk an additional 60 min per day.
  
  
  RESULTS
  The duration of inactivity and activity with OB individuals tended to be, respectively, higher and lower than that of CO individuals (P = .06). Both groups spent less time walking uphill/downhill than on the level (20%, 19%, vs. 61% of total walking duration, respectively, P < .001). However OB individuals spent less time walking uphill/downhill per day than CO (25 ± 15 and 38 ± 15 min/d, respectively, P < 0.05) and covered a shorter distance per day (3.8 km vs 5.2 km, P < 0.01).
  
  
  CONCLUSIONS
  BMI and outdoor topography should also be considered when prescribing extra walking in free-living conditions.
authors.affiliation: Dept of Physiology, Faculty of Biology and Medicine, University of Lausanne, Switzerland.
authors.forename: Minh Tuan
authors.initials: MT
authors.lastname: Nguyen D
authors.forename: Virgile
authors.initials: V
authors.lastname: Lecoultre
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Hills
authors.forename: Yves
authors.initials: Y
authors.lastname: Schutz
mesh_terms: D061725:Accelerometry; D000328:Adult; D015992:Body Mass Index; D004734:Energy Metabolism; D015444:Exercise; D005260:Female; D040362:Geographic Information Systems; D015438:Health Behavior; D006801:Humans; D008297:Male; D009765:Obesity / Q000453:epidemiology*; D012111:Residence Characteristics; D013997:Time Factors; D014186:Transportation; D014505:Urban Population / Q000706:statistics & numerical data*; D016138:Walking