title: Summer to winter variability in the step counts of normal weight and overweight adults living in the UK.
abstract: BACKGROUND
  This study investigated whether pedometer-determined activity varies between summer and winter in normal-weight and overweight adults.
  
  
  METHODS
  Forty-five normal-weight (58% female, age = 39.1 ± 12.4 years, BMI = 22.2 ± 2.1 kg/m²) and 51 overweight (49% female, age = 42.1 ± 12.5 years, BMI = 29.3 ± 4.5 kg/m²) participants completed a within-subject biseasonal pedometer study. All participants completed 2 4-week monitoring periods; 1 period in the summer and 1 period the following winter. Changes in step counts across seasons were calculated and compared for the 2 BMI groups.
  
  
  RESULTS
  Both BMI groups reported significant summer to winter reductions in step counts, with the magnitude of change being significantly greater in the normal-weight group (-1737 ± 2201 versus -781 ± 1673 steps/day, P = .02). Winter step counts did not differ significantly between the 2 groups (9250 ± 2845 versus 8974 ± 2709 steps/day, P = .63), whereas the normal-weight group reported a significantly higher mean daily step count in the summer (10986 ± 2858 versus 9755 ± 2874 steps/day, P = .04).
  
  
  CONCLUSIONS
  Both normal-weight and overweight individuals experienced a reduction in step counts between summer and winter; however, normal-weight individuals appear more susceptible to winter decreases in ambulatory activity, with the greatest seasonal change occurring on Sundays. Effective physical activity policies should be seasonally tailored to provide opportunities to encourage individuals to be more active during the winter, particularly on weekends.
authors.affiliation: School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, United Kingdom.
authors.forename: Stacy A
authors.initials: SA
authors.lastname: Clemes
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Hamilton
authors.forename: Paula L
authors.initials: PL
authors.lastname: Griffiths
mesh_terms: D056044:Actigraphy; D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D015992:Body Mass Index; D005260:Female; D006801:Humans; D056865:Ideal Body Weight; D008297:Male; D008875:Middle Aged; D050177:Overweight / Q000453:epidemiology* / Q000517:prevention & control; D012621:Seasons; D013997:Time Factors; D006113:United Kingdom / Q000453:epidemiology; D016138:Walking / Q000706:statistics & numerical data*; D055815:Young Adult