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.
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 Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
24
Sitting for 30 minutes
Performing a single session of high-intensity interval exercise on a cycle ergometer
Goldring Centre for High Performance Sport
Toronto, Ontario, Canada
Insulin area under the curve
Insulin area under the curve measured during glucose tolerance test
Time frame: 3 hours
Glucose area under the curve
Glucose area under the curve measured during glucose tolerance test
Time frame: 3 hours
Mean insulin concentration
Mean insulin concentration measured during glucose tolerance test
Time frame: 3 hours
Mean glucose concentration
Mean glucose concentration measured during glucose tolerance test
Time frame: 3 hours
Peak insulin concentration
Peak insulin concentration measured during the glucose tolerance test
Time frame: 3 hours
Peak glucose concentration
Peak insulin concentration measured during the glucose tolerance test
Time frame: 3 hours
Insulin:glucose ratio
Insulin to glucose ration measured during the glucose tolerance test
Time frame: 3 hours
Postprandial glucose oxidation
Postprandial glucose oxidation measured with a metabolic tracer
Time frame: 3 hours
Skeletal muscle glycogen content
Muscle glycogen use during exercise
Time frame: immediately before and after exercise
Skeletal muscle contractile signaling protein content
Measured via western blotting
Time frame: immediately before and after exercise
Skeletal muscle insulin signaling
Measured via western blotting
Time frame: 1hr into glucose tolerance test
Mitochondrial gene expression
Measured via Reverse transcription polymerase chain reaction
Time frame: 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
Time frame: 3hr post-exercise
Local muscle oxygenation
Muscle oxygenation (vastus lateralis) assessed with near-infrared spectroscopy (NIRS)
Time frame: During exercise
Local muscle oxygenation
Muscle oxygenation (vastus lateralis) assessed with NIRS during and following thigh cuff inflation
Time frame: Pre-exercise, immediately post-exercise and 2 hrs post-exercise
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.