ExerciseNCT06074003
Does Biological Sex Influence Insulin Sensitivity and Muscle Metabolism Following High-intensity Interval Exercise?
A study testing High-intensity interval exercise in people with Exercise, run by University of Toronto at 1 site in Canada.
Trial summary
High-intensity interval exercise (HIIE) is a type of exercise that involves alternating periods of intense exercise with periods of rest. HIIE has been shown to improve many aspects of cardiovascular and metabolic health in a time-efficient manner (e.g., only 20 minutes per exercise session). Read more about this study
- Who is it for?
- Ages 18 to 35 yearsHealthy volunteers can take part
- Conditions the study is for
- Exercise
- What is being tested?
- High-intensity interval exercise
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 24 participants
- Where
- 1 siteCanada
- Study dates
- 15 Oct 2023to 26 Jun 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 35 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 18-35 yrs
- VO2peak considered recreationally active as defined as 'fair' or 'good' (males: 41.6- 50.5ml/kg/min; females: 35-41.9 ml/kg/min) based on Canadian Society for Exercise Physiology (CSEP) normative fitness values.
- BMI between 18-27 kg/m2
- 1-3 structured exercise sessions/week, and not training for any specific sport
- Weight stable (within ± 2kg for at least 6 months)
- Eumenorrheic (female only), defined as menstrual cycle lengths ≥ 21 days and ≤ 35 days resulting in 9 or more consecutive periods per year)
- Non-smoker
Who cannot join
- Diagnosed with cardiovascular or metabolic disease, hyper- or hypogonadism, and/or polycystic ovarian syndrome (PCOS)
- The use of medication for managing blood glucose or lipid metabolism
- Current use of oral contraceptives or use within the last 3 months
- Irregular menstrual cycles (<21 days or >35 days)
- Pregnant, lactating, or menopausal
- Recreational smoking of any kind
Show all 9Show fewer
- Inability to perform the study exercise protocols or follow the pre-trial dietary or physical activity controls
- Taking medications affecting substrate metabolism (corticosteroids or nSAIDs)
- Actively engaging in a low-carbohydrate diet (e.g., ketogenic, Atkins)
Trial locations and contacts
1 site in 1 country.
Canada1 site
Goldring Centre for High Performance Sport
Toronto, Ontario, M5S2C9
About this study
High-intensity interval exercise (HIIE) is a type of exercise that involves alternating periods of intense exercise with periods of rest. HIIE has been shown to improve many aspects of cardiovascular and metabolic health in a time-efficient manner (e.g., only 20 minutes per exercise session). An important health benefit of exercise is improved blood sugar control, which can help reduce the risk of metabolic diseases like type 2 diabetes. A single session of HIIE has been shown to improve blood sugar in males, but it is unknown if females achieve the same health benefit. It is also not fully understood how exercise improves blood sugar in males and females. Therefore, the purpose of this project is 1) to determine if a single session of HIIE improves blood sugar control in males and females, and 2) to evaluate if changes in skeletal muscle can explain the beneficial effects of HIIE on blood sugar.
Read the detailed description
The primary purpose of this study is to determine if biological sex influences the effects of high-intensity interval exercise (HIIE) on insulin sensitivity and muscle mechanisms. The investigators will measure insulin sensitivity and muscle outcomes of participants on two separate occasions: 1) Following 30 minutes of sitting in the lab; and 2) Following a single session of HIIE on a stationary bike. Insulin sensitivity will be measured by taking blood samples after participants consume a sugary drink. Muscle outcomes will be measured by taking a small amount of muscle from the vastus lateralis (thigh) muscle. Groups of male and female participants will be recruited and tested using best practice guidelines for sex-based comparisons of exercise responses.
The study will advance knowledge regarding the potential for biological sex to influence the metabolic responses high-intensity exercise.
- Conditions
- Exercise
- Being tested
- Seated Rest (Non-exercise control), High-intensity interval exercise
- Medical subject headings
- Motor Activity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Seated Rest (Non-exercise control)Other
Sitting for 30 minutes
High-intensity interval exerciseOther
Performing a single session of high-intensity interval exercise on a cycle ergometer
| Study group | Role | What they receive |
|---|---|---|
| Females | Experimental | Female participant group Receives: Other: Seated Rest (Non-exercise control); Other: High-intensity interval exercise |
| Males | Experimental | Male participant group Receives: Other: Seated Rest (Non-exercise control); Other: High-intensity interval exercise |
What is being measured
The primary outcome is the main question the study is designed to answer.
Insulin area under the curve
Insulin area under the curve measured during glucose tolerance test
Measured: 3 hours
Secondary outcomes (14)
Glucose area under the curve
Glucose area under the curve measured during glucose tolerance test
Measured: 3 hours
Mean insulin concentration
Mean insulin concentration measured during glucose tolerance test
Measured: 3 hours
Mean glucose concentration
Mean glucose concentration measured during glucose tolerance test
Measured: 3 hours
Peak insulin concentration
Peak insulin concentration measured during the glucose tolerance test
Measured: 3 hours
Peak glucose concentration
Peak insulin concentration measured during the glucose tolerance test
Measured: 3 hours
Insulin:glucose ratio
Insulin to glucose ration measured during the glucose tolerance test
Measured: 3 hours
Postprandial glucose oxidation
Postprandial glucose oxidation measured with a metabolic tracer
Measured: 3 hours
Skeletal muscle glycogen content
Muscle glycogen use during exercise
Measured: immediately before and after exercise
Skeletal muscle contractile signaling protein content
Measured via western blotting
Measured: immediately before and after exercise
Skeletal muscle insulin signaling
Measured via western blotting
Measured: 1hr into glucose tolerance test
Mitochondrial gene expression
Measured via Reverse transcription polymerase chain reaction
Measured: Change from pre-exercise to 3hr post-exercise
Muscle protein synthesis rates
Muscle protein synthesis rates assessed by incorporation of oral stable isotope tracer following exercise
Measured: 3hr post-exercise
Local muscle oxygenation
Muscle oxygenation (vastus lateralis) assessed with near-infrared spectroscopy (NIRS)
Measured: During exercise
Local muscle oxygenation
Muscle oxygenation (vastus lateralis) assessed with NIRS during and following thigh cuff inflation
Measured: Pre-exercise, immediately post-exercise and 2 hrs post-exercise
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Oct 2023
- Study start15 Oct 2023
- Primary completion26 Jun 2025
- Study completion26 Jun 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ExerciseStudies of the same condition, open and under way.
- More trials run by University of TorontoThe 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
- Non-randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 24 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Toronto
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jenna Gillen, University of Toronto
- Investigators
- Stephanie Estafanos, MSc, Study director, University of Toronto
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06074003
- Sponsor's protocol ID
- 44435
- Status last verified
- Dec 2024
- First submitted
- 27 Sep 2023
- Last updated
- 19 Aug 2025
- Results posted
- No
- Data monitoring committee
- No
- 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 19 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Does Biological Sex Influence Insulin Sensitivity and Muscle Metabolism Following High-intensity Interval Exercise?
- ClinicalTrials.gov ID
- NCT06074003
- Acronym / sponsor ID
- 44435
- Conditions
- Exercise
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 24 participants (actual)
- Lead sponsor
- University of TorontoUniversity, hospital or other
- Study start
- 15 Oct 2023 (actual)
- Primary completion
- 26 Jun 2025 (actual)
- Study completion
- 26 Jun 2025 (actual)
- First posted
- 10 Oct 2023 (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.
High-intensity interval exercise (HIIE) is a type of exercise that involves alternating periods of intense exercise with periods of rest. HIIE has been shown to improve many aspects of cardiovascular and metabolic health in a time-efficient manner (e.g., only 20 minutes per exercise session). An important health benefit of exercise is improved blood sugar control, which can help reduce the risk of metabolic diseases like type 2 diabetes. A single session of HIIE has been shown to improve blood sugar in males, but it is unknown if females achieve the same health benefit. It is also not fully understood how exercise improves blood sugar in males and females. Therefore, the purpose of this project is 1) to determine if a single session of HIIE improves blood sugar control in males and females, and 2) to evaluate if changes in skeletal muscle can explain the beneficial effects of HIIE on blood sugar.
Detailed description
The primary purpose of this study is to determine if biological sex influences the effects of high-intensity interval exercise (HIIE) on insulin sensitivity and muscle mechanisms. The investigators will measure insulin sensitivity and muscle outcomes of participants on two separate occasions: 1) Following 30 minutes of sitting in the lab; and 2) Following a single session of HIIE on a stationary bike. Insulin sensitivity will be measured by taking blood samples after participants consume a sugary drink. Muscle outcomes will be measured by taking a small amount of muscle from the vastus lateralis (thigh) muscle. Groups of male and female participants will be recruited and tested using best practice guidelines for sex-based comparisons of exercise responses.
The study will advance knowledge regarding the potential for biological sex to influence the metabolic responses high-intensity exercise.
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Females | Experimental | Other: Seated Rest (Non-exercise control), Other: High-intensity interval exerciseFemale participant group |
| Males | Experimental | Other: Seated Rest (Non-exercise control), Other: High-intensity interval exerciseMale participant group |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (7 listed)
- 18-35 yrs
- VO2peak considered recreationally active as defined as 'fair' or 'good' (males: 41.6- 50.5ml/kg/min; females: 35-41.9 ml/kg/min) based on Canadian Society for Exercise Physiology (CSEP) normative fitness values.
- BMI between 18-27 kg/m2
- 1-3 structured exercise sessions/week, and not training for any specific sport
- Weight stable (within ± 2kg for at least 6 months)
Key exclusion criteria (9 listed)
- Diagnosed with cardiovascular or metabolic disease, hyper- or hypogonadism, and/or polycystic ovarian syndrome (PCOS)
- The use of medication for managing blood glucose or lipid metabolism
- Current use of oral contraceptives or use within the last 3 months
- Irregular menstrual cycles (<21 days or >35 days)
- Pregnant, lactating, or menopausal
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 |
|---|---|---|
| Seated Rest (Non-exercise control)Sitting for 30 minutes | Other | Females, Males |
| High-intensity interval exercisePerforming a single session of high-intensity interval exercise on a cycle ergometer | Other | Females, Males |
Primary outcome
Insulin area under the curve
Time frame: 3 hours
Insulin area under the curve measured during glucose tolerance test
14 secondary outcomes
Glucose area under the curve
Time frame: 3 hours
Mean insulin concentration
Time frame: 3 hours
Mean glucose concentration
Time frame: 3 hours
Peak insulin concentration
Time frame: 3 hours
Peak glucose concentration
Time frame: 3 hours
Insulin:glucose ratio
Time frame: 3 hours
Postprandial glucose oxidation
Time frame: 3 hours
Skeletal muscle glycogen content
Time frame: immediately before and after exercise
Skeletal muscle contractile signaling protein content
Time frame: immediately before and after exercise
Skeletal muscle insulin signaling
Time frame: 1hr into glucose tolerance test
Mitochondrial gene expression
Time frame: Change from pre-exercise to 3hr post-exercise
Muscle protein synthesis rates
Time frame: 3hr post-exercise
Local muscle oxygenation
Time frame: During exercise
Local muscle oxygenation
Time frame: Pre-exercise, immediately post-exercise and 2 hrs post-exercise
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Aug 2025.
- 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. This study is not recruiting at the moment.
Stephanie Estafanos, MSc study director
University of Toronto
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing High-intensity interval exercise in people with Exercise, run by University of Toronto 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 7 inclusion and 9 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 19 Aug 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Insulin area under the curve (time frame: 3 hours). 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 19 Aug 2025.