title: Pattern changes in step count accumulation and peak cadence due to a physical activity intervention.
abstract: OBJECTIVE
  The purpose was to determine if a 12-week weight loss intervention with a physical activity (PA) component would lead to changes in steps/day, step count accumulation patterns, and peak cadence.
  
  
  METHODS
  Randomized clinical trial.
  
  
  METHODS
  Overall, 121 overweight/obese White and African-American adults (ages 35-64yrs) were randomized to a diet education plus PA education and behavior change intervention group (DE+PA) or diet education and behavior change group (DE). The DE+PA intervention was designed to increase steps/day, and steps at moderate-to-vigorous intensity. The Actigraph GT3X+ accelerometer was used to measure steps accumulated in different cadence bands (1-19, 20-39, 40-59, 60-79, 80-99, 100-119, 120+ steps/min), and peak 1-min, 30-min and 60-min cadence. Pre- to post-intervention changes in steps/day, step count within each cadence band, and peak cadences were compared within groups using paired sample t-test and between groups after adjustment for baseline values of the same variable using ANCOVA.
  
  
  RESULTS
  Ninety participants had valid data (44 in the DE+PA group). Change in steps/day was not significantly different between the groups. However, participants in the DE+PA group accumulated significantly more steps at post-intervention in the 80-99, 100-119, and 120+ cadence bands, all p<0.02. The DE+PA group increased step counts accumulated within the 100-119 (463±1092 vs 56±546 step counts; p=0.01) and 120+ (390±999 vs 34±321 step counts; p=0.03) cadence bands, as well as peak 60-min cadence when compared to the DE group.
  
  
  CONCLUSIONS
  Non-significant changes in steps/day following a PA intervention may mask changes in steps accumulated at moderate-to-vigorous intensity cadences.
authors: Pennington Biomedical Research Center, USA; Syracuse University, USA.
authors: T V
authors: TV
authors: Barreira
authors: Pennington Biomedical Research Center, USA; Diabetes Research Centre, University of Leicester, UK.
authors: D M
authors: DM
authors: Harrington
authors: Pennington Biomedical Research Center, USA; Oregon State University, USA.
authors: J M
authors: JM
authors: Schuna
authors: Pennington Biomedical Research Center, USA.
authors: C
authors: C
authors: Tudor-Locke
authors: Pennington Biomedical Research Center, USA. Electronic address: peter.katzmarzyk@pbrc.edu.
authors: P T
authors: PT
authors: Katzmarzyk
mesh_terms: D061725:Accelerometry; D056044:Actigraphy; D000328:Adult; D001741:Black or African American; D005081:Exercise Therapy; D006801:Humans; D008875:Middle Aged; D009765:Obesity / Q000628:therapy*; D050177:Overweight / Q000628:therapy*; D016138:Walking; D061217:Weight Reduction Programs; D044465:White People
keywords: Activity counts; Peak cadence; Physical activity guidelines; Walking