title: Greater Adherence to Recommended Morning Physical Activity is Associated With Greater Total Intervention-Related Physical Activity Changes in Bariatric Surgery Patients.
abstract: This study examines whether performance of bout-related physical activity (PA) during morning hours is related to greater overall bout-related PA increases within a preoperative PA intervention for bariatric surgery (BS) patients.
  
  
  
  Participants with severe obesity (n = 33; mean age = 45.6 ± 9.6 years; BMI = 45.7 ± 7.0 kg/m2) seeking BS were randomized to and completed 6 weeks of preoperative PA counseling (retention = 82.5%). Participants were encouraged to walk daily at a moderate intensity in bouts ≥ 10 minutes during morning hours to overcome time-related obstacles and establish a PA habit. Timing and amount of bout-related moderate-to-vigorous PA (MVPA) was assessed via objective monitor at pre- and postintervention.
  
  
  
  Greater proportion of bout-related MVPA performed during morning hours (4:00 AM-12:00 PM) at postintervention was associated with larger total increases in bout-related MVPA minutes/day (β = .40, P = .03). At postintervention, a greater proportion of participants whose longest MVPA bouts occurred during morning hours (n = 11) achieved the public health guideline (ie, ≥150 bout-related MVPA minutes/week) versus those whose longest MVPA bouts occurred during nonmorning hours (n = 19; 63.6% vs. 26.3%, P = .04).
  
  
  
  Intervention-related increases in PA tended to be greatest when PA was performed in the morning. Morning exercise may be a viable strategy for promoting habitual PA in inactive BS patients.
authors.forename: Dale S
authors.initials: DS
authors.lastname: Bond
authors.forename: Hollie A
authors.initials: HA
authors.lastname: Raynor
authors.forename: J Graham
authors.initials: JG
authors.lastname: Thomas
authors.forename: Jessica
authors.initials: J
authors.lastname: Unick
authors.forename: Jennifer
authors.initials: J
authors.lastname: Webster
authors.forename: Beth
authors.initials: B
authors.lastname: Ryder
authors.forename: Sivamainthan
authors.initials: S
authors.lastname: Vithiananthan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D050110:Bariatric Surgery / Q000379:methods*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000628:therapy*; D055815:Young Adult
keywords: accelerometer; behavioral intervention; exercise; obesity