PreDiabetesNCT06365723
Effects of Walking in Greenspace and the Built Environment in Adults With Prediabetes: A Randomized Crossover Trial
A study testing Nature-based Walking and Built-environment/Commercial Walking in people with PreDiabetes and Heart Rate Variability (HRV), run by University of Minnesota at 3 sites in United States.
Trial summary
The goal of this randomized crossover trial is to compare the differences in psychological and physiological effects of walking in two different outdoor environments (urban/suburban commercial environments vs. urban/suburban nature areas/preserves) in adults with prediabetes. Read more about this study
- Who is it for?
- Ages 25 to 64 years
- Conditions the study is for
- PreDiabetes, Heart Rate Variability (HRV), Stress and Anxiety
- What is being tested?
- Nature-based Walking and Built-environment/Commercial Walking
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 216 participants
- Where
- 3 sitesUnited States
- Study dates
- 6 Jun 2024to 30 Nov 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 25 to 64 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- 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).
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- 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
Who cannot join
- 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.
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- 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.
Trial locations and contacts
3 sites in 1 country. Contact the study team or a site near you to ask about taking part.
United States3 sites, 3 recruiting
- Recruiting
Lake Forest Hospital
Lake Forest, Illinois, 60045
Molly Schau, mschau@nm.org
- Recruiting
Epidemiological Clinical Research Center
Minneapolis, Minnesota, 55415
Chris Hoefer, 612-626-9199
- Recruiting
Central DuPage Hospital
Winfield, Illinois, 60190
Molly Schau, mschau@nm.org
About this study
The goal of this randomized crossover trial is to compare the differences in psychological and physiological effects of walking in two different outdoor environments (urban/suburban commercial environments vs. urban/suburban nature areas/preserves) in adults with prediabetes. The main questions it aims to answer are:
- Do psychological measures of stress, anxiety, and affect improve more in one type of outdoor environment over the other?
- Do physiological measures of stress improve more in one type of outdoor environment over the other?
Read more
As this is a crossover trial, participants will serve as their own controls. Researchers will compare both the psychological and physiological effects walking in the two types of outdoor environments.
Participants will:
- Walk 150-minutes per week for six weeks in each of the two outdoor conditions.
- Visit the clinic four times, including before and after each six-week walking period.
- Collect saliva samples immediately proceeding or following the four clinic visits.
- Return to their pre-study level of physical activity for a 5-week washout period between each of the two walking interventions.
Read the detailed description
Approximately 92 million U.S. adults (~38% of population) have prediabetes (PreD). Because people with PreD are at high risk CMD, they are a target population for diabetes prevention programs. The focus is people with PreD because of their high risk for developing CMD and large numbers, providing an opportunity to investigate behavioral and environmental approaches as preventive measures in a well-defined population. Urbanization affords challenges and opportunities to public health that include exposure to obesogenic environments, air pollution, and psychosocial stressors. In healthy adults suggest exposure to nature has health benefits relative to exposure to built environments. Hypothesized mechanisms for health benefits of Greenspace exposure include increased physical activity (PA), attention restoration, stress reduction, and reduced exposure to pollution. Many of the health benefits are associated with reduced psychological and physiological stress leading to better autonomic functioning as assessed by heart rate variability (HRV) and other biomarkers. Multiple studies suggest that PA and exposure to natural environments may act together to improve health. Yet, aside from our preliminary studies, the investigators are not aware of any studies that examined how physical activity may interact with exposure to urban Greenspace ('Green') compared with built urban environments ('Gray'), to reduce stress and improve health. The purpose of this proposed study is to conduct a randomized crossover trial comparing differences in the psychosocial and physiological effects of walking in urban Green and Gray spaces in adults with PreD.
- Being tested
- Nature-based Walking, Built-environment/Commercial Walking
- Keywords
- walking intervention, built environment, outdoor environment, prediabetes, stress, urban
- Medical subject headings
- Prediabetic State, Anxiety Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Nature-based WalkingBehavioural
All participants will be asked to walk three to five times per week for 30-50 minutes per walk, totaling 150 min/week, at moderate intensity over a 6-week period in a designated nature-based, or 'green', urban environment.
Built-environment/Commercial WalkingBehavioural
All participants will be asked to walk three to five times per week for 30-50 minutes per walk, totaling 150 min/week, at moderate intensity over a 6-week period in a designated built-environment/commercial, or 'Gray', urban environment.
| Study group | Role | What they receive |
|---|---|---|
| Nature-based Walking then Built-environment/Commercial Walking | Experimental | People with prediabetes randomized to six weeks of nature-based walking followed by a five week washout, and then six weeks of built-environment/commercial-based walking Receives: Behavioral: Nature-based Walking; Behavioral: Built-environment/Commercial Walking |
| Built-environment/Commercial Walking then Nature-based Walking | Experimental | People with prediabetes randomized to six weeks of built-environment/commercial-based walking followed by a five week washout, and then six weeks of nature-based walking Receives: Behavioral: Nature-based Walking; Behavioral: Built-environment/Commercial Walking |
What is being measured
The primary outcome is the main question the study is designed to answer.
Measure of Anxiety
An Ecological Momentary Assessment of anxiety (rating level on a 0-10 point Likert scale) will be assessed pre/post each assessment walk.
Measured: Before and after each of the four assessment walks, which occur in weeks 4, 7, 15, and 18 (weeks 3 and 6 of each 6-week walking intervention).
Perceived stress assessment
Perceived stress will be measured using an Ecological Momentary Assessment of stress (rating level on a 0-10 point Likert scale) will be assessed pre/post each assessment walk.
Measured: Before and after each of the four assessment walks, which occur in weeks 4, 7, 15, and 18 (weeks 3 and 6 of each 6-week walking intervention).
Mood assessment
Mood will be evaluated using an Ecological Momentary Assessment of mood (i.e.. sadness, happiness, relaxation, mental energy, and physical energy) will be assessed pre/post each assessment walk (rating level on a 0-10 point Likert scale).
Measured: Before and after each of the four assessment walks, which occur in weeks 4, 7, 15, and 18 (weeks 3 and 6 of each 6-week walking intervention).
Restorativeness
Assessing the restorativeness of the walked environment (using the perceived restorativeness scale) after each of the four assessment walks.
Measured: Assessment given after each of the four assessment walks, which occur in weeks 4, 7, 15, and 18 (weeks 3 and 6 of each 6-week walking intervention).
Secondary outcomes (4)
Walking Heart Rate variability
Heart rate variability (HRV) will be measured before, during (within steady-state walking), and after each of the four assessment walks. We will use the Zephyr BioHarness and associated BioModule to complete these measurements. The a priori metric for analysis is the HRV during the walk between minutes 10 and 30.
Measured: Before, during, and after each of the four assessment walks, which occur in weeks 4, 7, 15, and 18 (weeks 3 and 6 of each 6-week walking intervention).
Salivary cortisol levels
Saliva will be collected using the passive drool collection method at the following daily times: (1) immediately upon waking; (2) 30-45 minutes after waking; and (3) 14 hours after waking. Sampling times allow for calculation of the cortisol awakening response and diurnal decline in cortisol, metrics well correlated with health outcomes. Salivary cortisol will be assayed using validated ELISA assays
Measured: Within 7 days of each of the four clinic visits which occur before and after each of the 6-week walking interventions (i.e. study weeks 1, 7, 12 and 18).
Ambient Particulate Matter
Ambient Particulate Matter will be assessed using the AirBeam3, a palm-sized air quality instrument that measures PM1, PM2.5, PM10, temperature, and relative humidity. It will be worn during each of the four assessment walks, measuring air-quality in real time as the participant is out on their walk.
Measured: During each of the four assessment walks, which occur in weeks 4, 7, 15, and 18 (weeks 3 and 6 of each 6-week walking intervention).
CMD risk
CMD risk score will be computed as the average of the z-scores comprised of systolic blood pressure, and fasting blood glucose, insulin, triglycerides, and HDL-cholesterol (reverse scored).
Measured: At each of the four clinic visits which occur before and after each of the 6-week walking interventions (i.e. study weeks 1, 7, 12 and 18).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Apr 2024
- Study start6 Jun 2024
- Primary completion30 Nov 2028 (estimated)
- Study completion30 Nov 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for PreDiabetesStudies of the same condition, open and under way.
- More trials run by University of MinnesotaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- The study is a randomized crossover trial with a 5-week washout period.
- Masking
- Single blind
- Who is masked
- Investigator
- Enrolment
- 216 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Minnesota
- Sponsor type
- University, hospital or other
- Collaborators
- Northwestern University
- Responsible party
- Sponsor
- Investigators
- Mark Pereira, PhD, Principal investigator, University of Minnesota
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06365723
- Sponsor's protocol ID
- SPH-2023-32410
- Status last verified
- Jun 2026
- First submitted
- 20 Mar 2024
- Last updated
- 18 Jun 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 18 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Walking in Greenspace and the Built Environment in Adults With Prediabetes: A Randomized Crossover Trial
- ClinicalTrials.gov ID
- NCT06365723
- Acronym / sponsor ID
- SPH-2023-32410
- Keywords
- walking intervention, built environment, outdoor environment, prediabetes, stress, urban
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 216 participants (estimated)
- Lead sponsor
- University of MinnesotaUniversity, hospital or other
- Collaborators
- Northwestern University
- Study start
- 6 Jun 2024 (actual)
- Primary completion
- 30 Nov 2028 (estimated)
- Study completion
- 30 Nov 2028 (estimated)
- First posted
- 15 Apr 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this randomized crossover trial is to compare the differences in psychological and physiological effects of walking in two different outdoor environments (urban/suburban commercial environments vs. urban/suburban nature areas/preserves) in adults with prediabetes. The main questions it aims to answer are:
- Do psychological measures of stress, anxiety, and affect improve more in one type of outdoor environment over the other?
- Do physiological measures of stress improve more in one type of outdoor environment over the other?
As this is a crossover trial, participants will serve as their own controls. Researchers will compare both the psychological and physiological effects walking in the two types of outdoor environments.
Participants will:
- Walk 150-minutes per week for six weeks in each of the two outdoor conditions.
- Visit the clinic four times, including before and after each six-week walking period.
- Collect saliva samples immediately proceeding or following the four clinic visits.
- Return to their pre-study level of physical activity for a 5-week washout period between each of the two walking interventions.
Detailed description
Approximately 92 million U.S. adults (~38% of population) have prediabetes (PreD). Because people with PreD are at high risk CMD, they are a target population for diabetes prevention programs. The focus is people with PreD because of their high risk for developing CMD and large numbers, providing an opportunity to investigate behavioral and environmental approaches as preventive measures in a well-defined population. Urbanization affords challenges and opportunities to public health that include exposure to obesogenic environments, air pollution, and psychosocial stressors. In healthy adults suggest exposure to nature has health benefits relative to exposure to built environments. Hypothesized mechanisms for health benefits of Greenspace exposure include increased physical activity (PA), attention restoration, stress reduction, and reduced exposure to pollution. Many of the health benefits are associated with reduced psychological and physiological stress leading to better autonomic functioning as assessed by heart rate variability (HRV) and other biomarkers. Multiple studies suggest that PA and exposure to natural environments may act together to improve health. Yet, aside from our preliminary studies, the investigators are not aware of any studies that examined how physical activity may interact with exposure to urban Greenspace ('Green') compared with built urban environments ('Gray'), to reduce stress and improve health. The purpose of this proposed study is to conduct a randomized crossover trial comparing differences in the psychosocial and physiological effects of walking in urban Green and Gray spaces in adults with PreD.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (investigator)
- Number of arms
- 2
- Model description
- The study is a randomized crossover trial with a 5-week washout period.
| Arm | Type | Receives |
|---|---|---|
| Nature-based Walking then Built-environment/Commercial Walking | Experimental | Behavioral: Nature-based Walking, Behavioral: Built-environment/Commercial WalkingPeople with prediabetes randomized to six weeks of nature-based walking followed by a five week washout, and then six weeks of built-environment/commercial-based walking |
| Built-environment/Commercial Walking then Nature-based Walking | Experimental | Behavioral: Nature-based Walking, Behavioral: Built-environment/Commercial WalkingPeople with prediabetes randomized to six weeks of built-environment/commercial-based walking followed by a five week washout, and then six weeks of nature-based walking |
Who may qualify
- Ages
- 25 to 64 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (12 listed)
- 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.
Key exclusion criteria (21 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Nature-based WalkingAll participants will be asked to walk three to five times per week for 30-50 minutes per walk, totaling 150 min/week, at moderate intensity over a 6-week period in a designated nature-based, or 'green', urban environment. | Behavioural | Built-environment/Commercial Walking then Nature-based Walking, Nature-based Walking then Built-environment/Commercial Walking |
| Built-environment/Commercial WalkingAll participants will be asked to walk three to five times per week for 30-50 minutes per walk, totaling 150 min/week, at moderate intensity over a 6-week period in a designated built-environment/commercial, or 'Gray', urban environment. | Behavioural | Built-environment/Commercial Walking then Nature-based Walking, Nature-based Walking then Built-environment/Commercial Walking |
Primary outcome
Measure of Anxiety
Time frame: Before and after each of the four assessment walks, which occur in weeks 4, 7, 15, and 18 (weeks 3 and 6 of each 6-week walking intervention).
An Ecological Momentary Assessment of anxiety (rating level on a 0-10 point Likert scale) will be assessed pre/post each assessment walk.
Perceived stress assessment
Time frame: Before and after each of the four assessment walks, which occur in weeks 4, 7, 15, and 18 (weeks 3 and 6 of each 6-week walking intervention).
Perceived stress will be measured using an Ecological Momentary Assessment of stress (rating level on a 0-10 point Likert scale) will be assessed pre/post each assessment walk.
Mood assessment
Time frame: Before and after each of the four assessment walks, which occur in weeks 4, 7, 15, and 18 (weeks 3 and 6 of each 6-week walking intervention).
Mood will be evaluated using an Ecological Momentary Assessment of mood (i.e.. sadness, happiness, relaxation, mental energy, and physical energy) will be assessed pre/post each assessment walk (rating level on a 0-10 point Likert scale).
Restorativeness
Time frame: Assessment given after each of the four assessment walks, which occur in weeks 4, 7, 15, and 18 (weeks 3 and 6 of each 6-week walking intervention).
Assessing the restorativeness of the walked environment (using the perceived restorativeness scale) after each of the four assessment walks.
4 secondary outcomes
Walking Heart Rate variability
Time frame: Before, during, and after each of the four assessment walks, which occur in weeks 4, 7, 15, and 18 (weeks 3 and 6 of each 6-week walking intervention).
Salivary cortisol levels
Time frame: Within 7 days of each of the four clinic visits which occur before and after each of the 6-week walking interventions (i.e. study weeks 1, 7, 12 and 18).
Ambient Particulate Matter
Time frame: During each of the four assessment walks, which occur in weeks 4, 7, 15, and 18 (weeks 3 and 6 of each 6-week walking intervention).
CMD risk
Time frame: At each of the four clinic visits which occur before and after each of the 6-week walking interventions (i.e. study weeks 1, 7, 12 and 18).
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Jun 2026.
- Study website for more information and contacts.Link provided by the sponsor.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Mark Pereira, PhD principal investigator
University of Minnesota
3 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Nature-based Walking and Built-environment/Commercial Walking in people with PreDiabetes and Heart Rate Variability (HRV), run by University of Minnesota at 3 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 12 inclusion and 21 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 18 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Sarah Rydell, MPH (612-437-6126, rydel004@umn.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Measure of Anxiety (time frame: Before and after each of the four assessment walks, which occur in weeks 4, 7, 15, and 18 (weeks 3 and 6 of each 6-week walking intervention).). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Jun 2026.