Break It Up: A Study Evaluating Breaking Up Daily Sedentary Behavior in Youth
Condition: Healthy; Obesity; Overweight
MeSH terms: Overweight
Study type: Interventional
Phase: Phase 2

Summary: 
      Background:

      Some studies have found that people can better process sugars when they take walking breaks.
      Studies have also found that children's attention and memory may improve after exercise. It
      is not known if short walking breaks have the same effects. Researchers want to study if
      breaking up sitting with walking for 6 days helps children s bodies use sugars and improves
      concentration.

      Objectives:

      To learn if breaking up sedentary (low-activity) time with short walking breaks over 6 days
      affects how children s bodies use sugar. To learn if breaking up sedentary time changes
      children s attention, memory, feelings, activity, or eating.

      Eligibility:

      Children ages 7-11 in general good health

      Design:

      Participants will be screened with:

        -  Medical history

        -  Physical exam

        -  Fasting blood tests. On 2 out of 7 total study visits, participants cannot eat or drink
           after 10 p.m. the night before.

        -  Full-body X-ray

        -  EKG (Electronic signals that record heart function through stickers)

        -  Treadmill exercise. Heart, blood pressure, and oxygen will be monitored.

        -  Questions about the child s health, socialization, and activity, and parent s education
           and economic status

        -  Picture vocabulary test

        -  Dietician meeting (Questions about eating habits)

      Participants will have visits on 6 consecutive days. Over that time, they will wear 2 devices
      to monitor blood sugar and activity (even while at home).

      Participants will have 5 after-school visits. These include:

        -  Health check

        -  Snack plus food for the next 24 hours

        -  Activity monitored

        -  3-hour sitting tests. Participants will do non-active things. Some will have 3-minute
           walks every 30 minutes.

        -  Cognitive tests and questions about mood and anxiety are given on days #1 & 5.

      Participants will fast before the last visit in the morning. They will have:

        -  9 blood draws by IV catheter. Participants will drink sugar water.

        -  Sitting test

        -  Activity monitored

        -  Meal (food buffet)
    

Detailed description: 
      Background:

      Sedentary behavior is defined as a set of low-intensity activities involving limited body
      movement (e.g.: TV viewing, prolonged sitting). Some studies have found higher levels of
      childhood sedentary behavior predict higher body mass index (BMI) and metabolic
      abnormalities. We and others have found that interrupting sitting with short, 2-3 minute
      bouts of moderate activity (walking) can improve glucose tolerance during a single session.
      Thus, interrupting sedentary behavior may be an intervention strategy to reduce health risks.

      Objective:

      We propose to conduct a randomized pilot study to assess whether interrupting sedentary
      behavior for 6 consecutive days provides sustained improvement in carbohydrate metabolism
      without negatively impacting executive function, attention, mood, anxiety, dietary

      intake or usual physical activity.

      Design & Population:

      Using a randomized parallel group design, children, ages 7-11 years, will complete an
      assigned randomized condition of either 6 consecutive days of 3 hours of monitored sedentary
      activity (sitting) or 6 consecutive days of 3 hours of interrupted sitting (in which they
      will be prompted to walk for 3 minutes every 30 minutes).

      Outcome measures:

      Twenty-four-hour continuous glucose monitoring and postprandial insulin incremental area
      under the curve (iAUC) on post-condition oral glucose tolerance testing will be the primary
      measures. Secondary measures include: postprandial glucose iAUC, executive function,
      attention, mood, anxiety, dietary intake, and free-living physical activity.

      Impact:

      This project will investigate if consecutive daily interruption of sitting behaviors improves
      glucose tolerance, a potential negative health consequences of sedentary behavior in
      children. If repeatedly interrupting sitting with short bouts has sustained beneficial
      effects among children, interventions examining the frequency, duration, and intensity of
      such interruptions could be developed for use in the community setting. Thus, these results
      have the potential to provide insight into novel behavioral intervention targets in youth.
    

Intervention name(s): Walking Bouts; Sedentary
Intervention type(s): Other; Other
Intervention description(s): Six daily 3 hour sessions with prompted 3-minute moderate-intensity walking bouts performed on a treadmill every 30 minutes throughout the 3 hour duration. There will be a total of 6 walking bouts (18 minutes total) each day. Moderate-intensity walking speed and grade will be selected to achieve 80% of the heart rate achieved at the ventilatory threshold as determined during a V02max test.; (Control 'intervention') Six daily 3 hour sessions with no physical activity (i.e. subject remains sedentary in seated or recumbent position) throughout the 3 hour duration.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Metabolism; Children; Walking Bouts; Glucose; Insulin