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Elevated Blood SugarNCT03576924

Power of Choice on Autonomy, Motivation, Exercise Adherence, and Cardiorespiratory Fitness

A study testing MICT, HIIT and CHOICE in people with Elevated Blood Sugar, run by University of British Columbia at 1 site in Canada.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

People with elevated blood sugar levels are at increased risk of developing chronic medical conditions such as obesity, type 2 diabetes, and cardiovascular disease. Improving cardiorespiratory fitness (CRF) in adults with elevated blood sugar levels is important for preventing the onset of such medical conditions. Read more about this study

Who is it for?
Ages 18 to 75 yearsHealthy volunteers can take part
Conditions the study is for
Elevated Blood Sugar
What is being tested?
MICT, HIIT and CHOICE
Could I receive a placebo?
No, everyone receives an active treatment
How many people
77 participants
Where
1 siteCanada
Study dates
1 Oct 2021to 31 Aug 2023
Phase
Interventional
Are there results?
Yes, posted in the registrySummary in the doctors' view

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 18 to 75 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • BMI 22-45 kg/m2;
  • HbA1c score indicative of elevated blood sugar (5.7-6.4%);
  • Blood pressure of <160/99 mm Hg assessed according to Canadian Hypertension Education Program guidelines;
  • Without diagnosed diabetes;
  • No prior history of cardiovascular disease;
  • Not on hormone replacement therapy;
  • Not on beta-blockers;
  • Cardiovascular medications (e.g., statins) will be allowed if patients are on stable therapy (6 months on same dose)

Who cannot join

  • Taking glucose-lowering medications (i.e. metformin);
  • Any explicit contraindications to exercise (e.g., musculoskeletal injury)

Trial locations and contacts

1 site in 1 country.

Canada1 site

  • University of British Columbia

    Kelowna, British Columbia, V1V 1V7

Other trials in Canada

About this study

Official title: The Power of Choice on Autonomy Support, Motivation, Exercise Adherence and Cardiorespiratory Fitness Among Adults With Elevated Blood Glucose

People with elevated blood sugar levels are at increased risk of developing chronic medical conditions such as obesity, type 2 diabetes, and cardiovascular disease. Improving cardiorespiratory fitness (CRF) in adults with elevated blood sugar levels is important for preventing the onset of such medical conditions. The primary aim of this study is to determine whether providing a choice between two different types of exercise in a diabetes prevention intervention improves perceived autonomy, exercise motivation, physical activity behavior, and subsequently CRF to a greater extent than imposed exercise among adults with elevated blood sugar.

Read the detailed description

This trial has been informed by self-determination theory. The theory states that individuals who choose their own activities report increased autonomy and internal reasons/motivations to change a behavior as opposed to external reasons (to satisfy another person's suggestions). Perceived autonomy support and internal motivation for performing a behavior are linked with improved long-term adherence to the behavior change, which subsequently leads to physiological adaptations such as an increase in CRF.

The primary outcome of this study is participants' perceived autonomy support after a 4-week diabetes prevention program. The secondary outcomes are 1) changes in exercise-related motivation from baseline to immediately post-intervention and 6-months post-intervention, 2) physical activity behavior 6-months post-intervention while controlling for baseline values, and 3) CRF 6-months post-intervention while controlling for baseline values. Seventy-seven low-active adults between 18-75 years of age with elevated blood sugar levels (HbA1c between 5.7%-6.4% or American Diabetes Association risk assessment >5) have been randomized to a 4-week supervised intervention involving behavioral counseling and one of three exercise conditions: 1) imposed high-intensity interval training (HIIT; n=26); 2) imposed moderate-intensity continuous training (MICT; n=26), or 3) choice between MICT or HIIT (CHOICE; n=24). It is hypothesized that when compared to HIIT and MICT, the CHOICE condition will have greater perceived autonomy support immediately after the 4-week intervention, display more internal motivation immediately after the 4-week intervention, and show greater improvements in physical activity adherence and CRF 6-months post-intervention. This proposed trial will provide theory- and evidence-based information whether providing choice for engaging in HIIT or MICT is associated with greater improvements in perceived autonomy support, motivation regulation, physical activity behavior, and CRF.

Being tested
MICT, HIIT, CHOICE
Keywords
Autonomy Support, Exercise Motivation, Physical Activity Adherence, Cardiorespiratory Fitness, Prediabetes
Medical subject headings
Hyperglycemia, Prediabetic State

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • MICTBehavioural

    Individuals randomized to MICT will be asked to engage in only MICT 5 times/week for 30 min/session at 60-70% of heart rate max, consistent with physical activity guidelines of 150 min/week of moderate activity. Individuals are asked to engage in only MICT exercise during the 4-week supervised and unsupervised exercise sessions. During the supervised exercise the intensity will be based on the heart rate (HR) monitors and psychophysiological responses of perceived exertion. The exercise training is paired with 30-50 minutes of behavioral counselling that is identical for all three interventions.

  • HIITBehavioural

    Individuals randomized to HIIT will be asked to engage in only HIIT 5 times/week for 4 weeks. HIIT consists of 5 repeated vigorous intervals of 1-min duration at 80-90% of heart rate max interspersed with 1-min recovery periods. A 3-min warm-up and 2-min cool-down are also included, for a total session duration of 15 minutes. This matches the guidelines of 75 min of vigorous exercise per week. During the supervised exercise sessions, intensity will be based on HR monitors and psychophysiological responses of perceived exertion. The exercise training is paired with 30-50 minutes of behavioral counselling that is identical for all three interventions.

  • CHOICEBehavioural

    Participants will first be familiarized with HIIT and MICT in a randomized, counter-balanced order during supervised sessions 1 and 2, and will subsequently self-select the exercise type for the supervised and unsupervised exercise sessions. The HIIT and MICT protocols will match to the parallel imposed conditions. During the supervised exercise, intensity will also be based on HR monitors and psychophysiological responses of perceived exertion. The exercise training is paired with 30-50 minutes of behavioral counselling that is identical for all three interventions.

Study groups in NCT03576924
Study groupRoleWhat they receive
MICTActive comparatorContinuous exercise for 30 minutes per session at 60-70% of heart rate max for five times per week, consistent with physical activity guidelines that advocate 150 minutes per week of moderate activity.
Receives: Behavioral: MICT
HIITActive comparatorFive repeated vigorous intervals of 1-min duration at 80-90% of heart rate max interspersed with 1-min recovery periods; 3-min warm-up and 2-min cool-down, making the total session duration 15 minutes for five times/week, equated to match the guidelines of 75 min of vigorous exercise per week.
Receives: Behavioral: HIIT
CHOICEExperimentalParticipants will be introduced to HIIT and MICT during sessions 1 and 2 of the 4-week intervention in a counterbalanced randomized order, and will thereafter self-select one of the two exercise types for remaining sessions. Exercise will be matched to the parallel imposed conditions.
Receives: Behavioral: CHOICE

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Perceived Autonomy Support

    Individual participants' perceived autonomy support will be measured using the Learning Climate Questionnaire (LCQ) adapted by Williams and Deci. The LCQ is a 15-item self-report questionnaire that measures perceived autonomy support and has been previously validated and shown to have strong internal reliability. The questionnaire uses a 7-point Likert scale ranging from 1 "strongly disagree" to 7 "strongly agree". For this study, the anchoring questions are modified to replace the term "instructor" with "coach". Scoring of individual results is done by averaging individual responses after reverse-coding item #13, with a minimum score of 1 and a maximum score of 7. Higher scores indicate a higher perception of autonomy support.

    Measured: Four weeks post-intervention.

Secondary outcomes (5)

  1. Change in Exercise Motivation Regulation

    Participants' change in motivation regulation from baseline to post-intervention and subsequently 6 months later is measured using the Behavioral Regulation in Exercise Questionnaire-2 (BREQ-2). The BREQ-2 is a 19-item self-report questionnaire that measures one's motivation to exercise. The questionnaire uses a 5-point Likert scale ranging from 0 "not true for me" to 4 "very true for me". The relative autonomy index (RAI) is used to provide an index of the degree to which participants feel self-determined ranging from a minimum score of -24 to a maximum score of +20, with higher positive scores indicating more autonomous forms of motivation regulation. The RAI is calculated by first averaging each subscale, then multiplying each average by a subscale weighting, and subsequently summing the weighted subscale scores. Weighting for each subscale are as follows: amotivation (-3), external regulation (-2), introjected regulation (-1), identified regulation (+2), intrinsic regulation (+3).

    Measured: Baseline, four weeks post-intervention, and 6 months post-intervention

  2. Change in Physical Activity Behavior (Self-Report)

    Change in physical activity behavior from baseline to 6 months later will be measured using the Godin Leisure-Time Exercise Questionnaire (GLTEQ). The GLTEQ requires individuals to report their frequency of engaging in strenuous, moderate, and mild exercise during a typical week in bouts of 15 minutes or longer. Scoring of the GLTEQ consists of first multiplying reported frequencies by their related metabolic equivalent (MET) values (strenuous: 9METs, moderate: 5METs, mild: 3METs), and then summing the products for a total score. Interpretation of the scores follows the categories proposed by Godin, where a score of 24 units or higher indicates an individual is active, a score between 14 and 23 indicates an individual is moderately active, and a score below 14 indicates an individual is insufficiently active. The minimum score is 0 and there is no maximum score. Higher scores indicate higher levels of physical activity behavior.

    Measured: Baseline, 6-months after the intervention

  3. Change in Physical Activity Behavior (Accelerometry)

    Change in physical activity behavior from baseline to 6 months later will also be measured using 7-day triaxial accelerometry data. Participants wear an Actigraph GT3X-BT for seven consecutive days at the top of their right hip at a sampling rate of 100Hz. Accelerometry data is considered valid if the participant wears the accelerometer for a minimum of 10 hours/day and at least 4 of the 7 days of the week. Non-wear time is defined as any period of 60 minutes or longer with no recorded activity counts. Physical activity is measured by summing activity counts in 60-second epochs, and cut-off activity count thresholds for defining intensity follows Troiano and colleagues' convention. Free-living physical activity behavior is operationalized as average daily minutes of MVPA and is calculated by summing both moderate and vigorous activity count minutes and subsequently dividing by the number of valid wear days.

    Measured: Baseline, 6 months after the intervention

  4. Change in Physical Activity Behavior (Fitbit)

    A wearable activity tracker (Fitbit Luxe™) is also provided to each participant to track change in physical activity behavior from baseline to 6 months later in free-living conditions. We define a valid wear day as any day with a minimum of 10 hours of wear time determined by continuous minute-by-minute heart rate recordings. Non-wear time is defined as a period of 60 continuous minutes with no heart rate recordings. A minimum of 4 out of 7 consecutive days of the week are required for the week to be considered valid. Free-living physical activity behavior is operationalized as average daily minutes of MVPA and is calculated by summing the daily minutes spent in moderate and intense activities per day and subsequently dividing by the number of valid wear days. Activity intensity levels are determined by using Fitbit-derived algorithms, and number of minutes per day at each intensity level are imported into Fitabase.

    Measured: Baseline, 6 months after intervention

  5. Change in Cardiorespiratory Fitness

    Participants' change in cardiorespiratory fitness (CRF) from baseline to 6 months later is calculated based on the minutes and seconds participants are able to achieve in submaximal 12-lead ECG stress tests performed at a cardiac rehabilitation clinic. Calculation of CRF is conducted according to Bruce and colleagues' equation for estimated maximal volume of oxygen intake (VO2max) in mL/(kg*min). Calculations are stratified by biological sex, where w is the weighting factor for sex (1=men; 2=women) and t is the duration of the protocol in seconds:

    VO2max=6.70-2.82w+0.056t

    Measured: Baseline, 6 months after intervention

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted5 Jul 2018
  2. Study start1 Oct 2021
  3. Primary completion31 Aug 2023
  4. Study completion31 Aug 2023

Resources

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
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Model description
This is a single-centre, 3-arm parallel-group randomized trial.
Masking
None (open label)
Enrolment
77 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03576924
Sponsor's protocol ID
G-18-0022225
Status last verified
Apr 2025
First submitted
21 Jun 2018
Last updated
2 May 2025
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Little JP, Safdar A, Wilkin GP, Tarnopolsky MA, Gibala MJ. A practical model of low-volume high-intensity interval training induces mitochondrial biogenesis in human skeletal muscle: potential mechanisms. J Physiol. 2010 Mar 15;588(Pt 6):1011-22. doi: 10.1113/jphysiol.2009.181743. Epub 2010 Jan 25.

    PubMed 20100740

  • Little JP, Gillen JB, Percival ME, Safdar A, Tarnopolsky MA, Punthakee Z, Jung ME, Gibala MJ. Low-volume high-intensity interval training reduces hyperglycemia and increases muscle mitochondrial capacity in patients with type 2 diabetes. J Appl Physiol (1985). 2011 Dec;111(6):1554-60. doi: 10.1152/japplphysiol.00921.2011. Epub 2011 Aug 25.

    PubMed 21868679

  • Hood MS, Little JP, Tarnopolsky MA, Myslik F, Gibala MJ. Low-volume interval training improves muscle oxidative capacity in sedentary adults. Med Sci Sports Exerc. 2011 Oct;43(10):1849-56. doi: 10.1249/MSS.0b013e3182199834.

    PubMed 21448086

  • Kodama S, Saito K, Tanaka S, Maki M, Yachi Y, Asumi M, Sugawara A, Totsuka K, Shimano H, Ohashi Y, Yamada N, Sone H. Cardiorespiratory fitness as a quantitative predictor of all-cause mortality and cardiovascular events in healthy men and women: a meta-analysis. JAMA. 2009 May 20;301(19):2024-35. doi: 10.1001/jama.2009.681.

    PubMed 19454641

  • O'Donovan G, Owen A, Bird SR, Kearney EM, Nevill AM, Jones DW, Woolf-May K. Changes in cardiorespiratory fitness and coronary heart disease risk factors following 24 wk of moderate- or high-intensity exercise of equal energy cost. J Appl Physiol (1985). 2005 May;98(5):1619-25. doi: 10.1152/japplphysiol.01310.2004. Epub 2005 Jan 7.

    PubMed 15640382

  • Jung ME, Bourne JE, Little JP. Where does HIT fit? An examination of the affective response to high-intensity intervals in comparison to continuous moderate- and continuous vigorous-intensity exercise in the exercise intensity-affect continuum. PLoS One. 2014 Dec 8;9(12):e114541. doi: 10.1371/journal.pone.0114541. eCollection 2014.

    PubMed 25486273

  • Jung ME, Bourne JE, Beauchamp MR, Robinson E, Little JP. High-intensity interval training as an efficacious alternative to moderate-intensity continuous training for adults with prediabetes. J Diabetes Res. 2015;2015:191595. doi: 10.1155/2015/191595. Epub 2015 Mar 30.

    PubMed 25918728

  • National Research Council (US) Panel on Handling Missing Data in Clinical Trials. The Prevention and Treatment of Missing Data in Clinical Trials. Washington (DC): National Academies Press (US); 2010. Available from http://www.ncbi.nlm.nih.gov/books/NBK209904/

    PubMed 24983040

  • Preacher KJ, Hayes AF. SPSS and SAS procedures for estimating indirect effects in simple mediation models. Behav Res Methods Instrum Comput. 2004 Nov;36(4):717-31. doi: 10.3758/bf03206553.

    PubMed 15641418

Questions about this trial

What is this clinical trial studying?

A study testing MICT, HIIT and CHOICE in people with Elevated Blood Sugar, run by University of British Columbia at 1 site in Canada.

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 8 inclusion and 2 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: finished, as of the sponsor's last update on 2 May 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Canada. 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?

Yes. Results are posted in the registry (first posted 2 May 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Perceived Autonomy Support (time frame: Four weeks post-intervention.). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT03576924, which also lists 9 linked publications.

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 2 May 2025.

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