Walking Before or After Breakfast - Which is Better to Improve Health in Overweight Individuals?
Condition: Metabolic Disease; Insulin Resistance
MeSH terms: Insulin Resistance; Metabolic Diseases
Study type: Interventional

Summary: 
      The aim of this study is to investigate the effectiveness of a home-based walking-based
      exercise intervention undertaken in the fed or fasted state to improve glycaemic control in
      overweight and obese individuals. This study will evaluate the adherence and compliance to
      this "real-world" exercise programme that requires no face-to-face contact with the research
      team. It is also hypothesised that individuals who exercise before breakfast (fasted) will
      see greater improvements in glycaemic control than those who exercise after breakfast.
    

Detailed description: 
      Individuals with a BMI above 28 will be recruited to investigate whether a home-based walking
      exercise intervention in the fasted or fed state is feasible to implement into real-world
      situation. Secondary to that, this study will investigate whether a fasted or fed
      intervention more effective for improving metabolic health. To do this, individuals will
      provide written consent, and then carry out baseline measures in their own home:

      Waist-to-hip ratio and weight: Participants will be provided with a tape measure to measure
      waist circumference and hip circumference. From this, waist-to-hip ratio will be calculated.
      Additionally, participants will be asked to use their own scales to provide their weight (if
      they don't have any they will be provided).

      CGM: Participants will receive a continuous blood glucose monitor and be directed over teams
      how to fit this. One will be worn for two weeks in weeks 0 and 1 and another will be worn for
      two weeks in weeks 12 and 13.

      Diet: Participants will receive a food diary to record their habitual dietary intake for
      three days (24 hours after the CGM is fitted). During the first week on the intervention they
      will also be asked to write down what they eat for lunch on the days they exercise.

      Fitness test: Participants will receive a polar beat heart rate monitor. They will be asked
      to complete tthe harvard step test wearing the HR monitor at least 48 hours before they begin
      the intervention.

      Exercise intervention:

      Pairs of participants from each group (matched for gender, age, BMI and) will be randomized
      to undertake 12 weeks of steady walking in either a fasted state (before breakfast each day)
      or a fed state (after breakfast each day). They will be asked to eat the same breakfast on
      each day they complete the exercise, whether it is before or after.

      Walking sessions will be 4 times per week and will be two continuous sessions (~50% HR max)
      and two interval sessions (3 minutes at 40% HR max, 3 minutes 80% HR max) monitored by the
      polar beat app. Participants will initially walk for 30 minute sessions in week 1 and this
      will increase by 5 minutes each week until they are completing 4x 60 minute sessions per week
      (see table.1).

      A CGM will be in place during week 1 to measure the glycaemic response to exercise. And a
      second CGM will be inserted at the beginning of week 12 to see the changes in glycaemic
      control on exercise days and will remain in place for post-intervention CGM monitoring.
    

Intervention name(s): Exercise
Intervention type(s): Behavioral
Intervention description(s): Both groups complete the exercise intervention identically, but one is in the fasted state and one is in the fed state.
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention