Does Biological Sex Influence Insulin Sensitivity and Muscle Metabolism Following High-intensity Interval Exercise?
- Conditions
- Exercise
- Interventions
- Other: Seated Rest (Non-exercise control)Other: High-intensity interval exercise
- Registration Number
- NCT06074003
- Lead Sponsor
- University of Toronto
- 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.
Recruitment & Eligibility
- Status
- RECRUITING
- Sex
- All
- Target Recruitment
- 24
- 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
- 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)
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Arm && Interventions
Group Intervention Description Females High-intensity interval exercise Female participant group Males High-intensity interval exercise Male participant group Females Seated Rest (Non-exercise control) Female participant group Males Seated Rest (Non-exercise control) Male participant group
- Primary Outcome Measures
Name Time Method Insulin area under the curve 3 hours Insulin area under the curve measured during glucose tolerance test
- Secondary Outcome Measures
Name Time Method Glucose area under the curve 3 hours Glucose area under the curve measured during glucose tolerance test
Insulin:glucose ratio 3 hours Insulin to glucose ration measured during the glucose tolerance test
Mean glucose concentration 3 hours Mean glucose concentration measured during glucose tolerance test
Peak insulin concentration 3 hours Peak insulin concentration measured during the glucose tolerance test
Skeletal muscle glycogen content immediately before and after exercise Muscle glycogen use during exercise
Skeletal muscle insulin signaling 1hr into glucose tolerance test Measured via western blotting
Local muscle oxygenation Pre-exercise, immediately post-exercise and 2 hrs post-exercise Muscle oxygenation (vastus lateralis) assessed with NIRS during and following thigh cuff inflation
Skeletal muscle contractile signaling protein content immediately before and after exercise Measured via western blotting
Mitochondrial gene expression Change from pre-exercise to 3hr post-exercise Measured via Reverse transcription polymerase chain reaction
Mean insulin concentration 3 hours Mean insulin concentration measured during glucose tolerance test
Postprandial glucose oxidation 3 hours Postprandial glucose oxidation measured with a metabolic tracer
Muscle protein synthesis rates 3hr post-exercise Muscle protein synthesis rates assessed by incorporation of oral stable isotope tracer following exercise
Peak glucose concentration 3 hours Peak insulin concentration measured during the glucose tolerance test
Trial Locations
- Locations (1)
Goldring Centre for High Performance Sport
🇨🇦Toronto, Ontario, Canada