Clinical trial NCT06074003: Does Biological Sex Influence Insulin Sensitivity and Muscle Metabolism Following High-intensity Interval Exercise?
Official title: Does Biological Sex Influence Insulin Sensitivity and Muscle Metabolism Following High-intensity Interval Exercise?
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Exercise
Lead sponsor: University of Toronto
Sponsor class: OTHER
First posted: 2023-10-10
Enrollment: 24
Sex: ALL
Minimum age (years): 18
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief 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). 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.

Eligibility criteria: Inclusion Criteria:

* 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

Exclusion Criteria:

* 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
* 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)

Primary outcomes:
measure: Insulin area under the curve
timeFrame: 3 hours
Secondary outcomes:
measure: Glucose area under the curve
timeFrame: 3 hours
measure: Mean insulin concentration
timeFrame: 3 hours
measure: Mean glucose concentration
timeFrame: 3 hours
measure: Peak insulin concentration
timeFrame: 3 hours
measure: Peak glucose concentration
timeFrame: 3 hours
measure: Insulin:glucose ratio
timeFrame: 3 hours
measure: Postprandial glucose oxidation
timeFrame: 3 hours
measure: Skeletal muscle glycogen content
timeFrame: immediately before and after exercise
measure: Skeletal muscle contractile signaling protein content
timeFrame: immediately before and after exercise
measure: Skeletal muscle insulin signaling
timeFrame: 1hr into glucose tolerance test
measure: Mitochondrial gene expression
timeFrame: Change from pre-exercise to 3hr post-exercise
measure: Muscle protein synthesis rates
timeFrame: 3hr post-exercise
measure: Local muscle oxygenation
timeFrame: During exercise
measure: Local muscle oxygenation
timeFrame: Pre-exercise, immediately post-exercise and 2 hrs post-exercise
Other outcomes:
Locations:
city: Toronto
country: Canada
facility: Goldring Centre for High Performance Sport
state: Ontario
Study officials:
affiliation: University of Toronto
name: Stephanie Estafanos, MSc
role: STUDY_DIRECTOR
References: