Effects of Walking in Greenspace and the Built Environment in Adults With Prediabetes: A Randomized Crossover Trial

Inclusion criteria

• 25-64 years old.
• Classified as overweight or obese with BMI 20.0-39.9 kg/m2 per self-report and a BMI of 20.0- 41.9 kg/m2 upon actual measure.
• Documentation\* of a PreD diagnosis within one year of enrollment by physician or primary care provider based on lab tests showing a fasted blood glucose of 100-125 mg/dL, a 2-hour oral glucose tolerance test of 140-199 mg/dL, or an HbA1c level of 5.7%-6.49%271; OR a study screening lab value of HbA1C within the aforementioned range.
• Currently engaged in ≤100 min/week of moderate to vigorous exercise -confirmed via a 7-day activity recall.
• No exercise contraindications as assessed by the Physical Activity Readiness Questionnaire (PAR-Q) -this Questionnaire involves seven "yes" or "no" questions regarding an individual's health status. Answering "yes" to any one of these questions may require a prospective participant to acquire a written doctor's note stating they can safely participate in the trial's exercise intervention. The participant would not be enrolled until this doctor's note is received.
• Stable weight over the last 3 months (less than 10% change).
• Not currently pregnant, planning to become pregnant, or currently breastfeeding.
• Willing to maintain current dietary and exercise habits, aside from any changes to be made per the study exercise protocol.
• Must own a smartphone and be willing and able to download the Garmin Connect app
• Ability to speak and understand English.
• Any level of income
• Any race/ethnicity

Exclusion criteria

• Individuals \<25 or \>64: younger individuals may have not yet reached physiological maturity and in whom PreD prevalence is low; older individuals are more likely to have contraindications to PA and other comorbidities.
• BMI \<20 or ≥42.
• Individuals with an HbA1c level \<5.7% or \>6.4%.
• Currently engaged in \>100 min/wk of PA.
• Individuals with contraindications to exercise participation as indicated by the PAR-Q.
• A self-reported physical/mental disability that would prevent them from being able to adhere to the intervention.
• Past or current diagnosis of Diabetes (Type 1, 1.5 or 2) or use of diabetic medications (e.g. medications to control blood sugar)
• Any history of a cardiovascular disease event (e.g. heart attack, ablation, pacemaker, stroke)
• Current treatment for cancer or heart disease (lipid and hypertensive medications acceptable but will be tracked closely).
• Any change within the last 3 months, or anticipated changes, of any medications that would affect study outcomes (e.g. medications for lipids, blood pressure, anxiety, depression)
• The use of any medication that significantly interferes with the autonomic nervous system
• Current tobacco or nicotine users, or those who have quit within the last six months
• Excessive alcohol (on average\>1 drinks/day for women and \>2 drinks/day for men) or excessive recreational drug use (reported usage of once a week or more).
• Unstable weight over the last three months (\>10% change).
• Those with major surgery planned or recent history of bariatric surgery (within last 2 years) or a history of other medical interventions that would interfere with study outcomes
• Currently within one-year postpartum, currently pregnant, or planning to become pregnant during the study period.
• Currently breastfeeding.
• Unwilling to comply with study randomization procedures.
• Unwilling to maintain current dietary and exercise habits, aside from any changes to be made per the study exercise protocol.
• Current participation in another interventional clinical trial.
• Previous randomization in this study.