The Relationship Between Exercise Frequency, Intensity, and Restoration of Cardiometabolic Health
- Conditions
- Overweight or Obesity
- Interventions
- Behavioral: Endurance Exercise Training (END)Behavioral: Sprint Exercise Training (SIT)
- Registration Number
- NCT03376685
- Lead Sponsor
- University of Guelph
- Brief Summary
Regular physical activity is well established to decrease the risk of cardiometabolic diseases. While research has characterized responses based on exercise intensity, many beneficial effects of exercise are transient in nature, and therefore exercise frequency may play an important, yet currently under-appreciated, role in improving health. The purpose of this study is to determine the efficacy of 6-week high-frequency endurance (END) or low-frequency sprint (SIT) training with respect to reducing clinically relevant cardiometabolic risk factors in overweight/obese males. It is hypothesized that END, performed at a greater frequency than SIT, will markedly improve cardiometabolic health, while low-frequency SIT will not.
- Detailed Description
Involvement in regular physical activity is known to elicit systemic adaptations and reduce the risk of cardiometabolic diseases, including hypertension, obesity, dyslipidemia, and hyperglycemia. Traditional physical activity recommendations suggest that 150 minutes of moderate-intensity continuous endurance (END) exercise dispersed over 5 days per week is sufficient to improve physical fitness in adults. However, given the commonly cited barrier of "lack of time," literature has recently focused on time effective sprint interval training (SIT), obtaining equivalent increases in aerobic capacity and acute glycemic regulation compared to classical END exercise when protocols are work-matched. Despite these similarities, END is conducive to daily sessions not feasible of SIT. As improvements in many clinically relevant risk factors are transient in nature following exercise, it remains imperative to assess the implications of variable frequency exercise regimes performed as per general practice (i.e. high-frequency END, low-frequency SIT). Furthermore, improvements in cardiovascular outcomes following END have been shown, in some instances, to be absent in response to SIT, suggesting END may be more beneficial for cardiovascular health. Therefore, the current study aims to assess several markers of cardiovascular (aerobic capacity, blood pressure, arterial stiffness, vascular endothelial function) and metabolic (glucose tolerance, lipid tolerance, body composition) health following 6-weeks of high-frequency END or low-frequency SIT, performed as per general practice. Combined, this research will provide important insight into the under-appreciated role of exercise frequency for improving cardiometabolic health.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- Male
- Target Recruitment
- 23
- Male, aged 18-70 years
- Body mass index (BMI) > 25 kg/m^2 (classified as overweight or obese)
- Sedentary (<100 minutes moderate physical activity per week)
- Approval for vigorous exercise via physical activity readiness questionnaire (PARQ+)
- Prescribed with glucose lowering medications
- Smoker
- Not cleared for physical activity
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Endurance Exercise Training (END) Endurance Exercise Training (END) This group is performing END training for 6 weeks in duration. Intervention: Behavioral: Endurance Exercise Training (END) Sprint Exercise Training (SIT) Sprint Exercise Training (SIT) This group is performing SIT training for 6 weeks in duration. Intervention: Behavioral: Sprint Exercise Training (SIT)
- Primary Outcome Measures
Name Time Method Cardiorespiratory fitness Baseline (pre-training) vs. week 6 (post-training) Assessed via VO2 peak test, to determine the change in cardiorespiratory fitness following 6-weeks of exercise training
Free-living glycemic regulation Baseline (pre-training) vs. week 6 (post-training) Assessed via continuous glucose monitoring (CGM), to determine the change in free-living glycemic regulation following 6-weeks of exercise training
Glucose tolerance Baseline (pre-training) vs. week 6 (post-training) Assessed via an oral glucose tolerance test (OGTT) to determine changes in standardized glycemic regulation following 6-weeks of exercise training
- Secondary Outcome Measures
Name Time Method Blood lipids Baseline (pre-training) vs. week 6 (post-training) Blood lipid profile from fasted venous blood sampling, including high-density lipoproteins (HDL), low-density lipoproteins (LDL), high-sensitivity C-reactive protein (Hs-CRP), cholesterol, non-HDL cholesterol, triglycerides (TAG), free-fatty acids (FFA), and cholesterol/HDL ratio
Arterial stiffness Baseline (pre-training) vs. week 6 (post-training) Assessed via carotid-femoral pulse wave velocity (PWV)
HbA1C Baseline (pre-training) vs. week 6 (post-training) Change in HbA1C assessed via fasted venous blood sampling, following 6-weeks of exercise training
Arterial stiffness acutely post-exercise Acutely pre-exercise vs. post-exercise in week 1 of training Assessed via carotid-femoral pulse wave velocity (PWV) following a single bout of exercise in week 1 of each group
Brachial artery vascular function Baseline (pre-training) vs. week 6 (post-training) Assessed via brachial artery flow mediated dilation (FMD) following 6-weeks of exercise training
Daily sedentary/active time Baseline (pre-training), week 1 (of training), week 6 (post-training) Assessed via accelerometer
Free-living glycemic regulation during the first week of exercise training Baseline (pre-training) vs. week 1 (of training) Assessed via continuous glucose monitoring (CGM)
Post-prandial blood lipids Baseline (pre-training) vs. week 6 (post-training) Assessed following the consumption of an oral fat tolerance test (OFTT). Blood lipid responses include triglycerides (TAG) and free fatty acids (FFA), assessing the influence of 6-weeks of exercise training on these parameters
Blood pressure Baseline (pre-training) vs. week 6 (post-training) Assessed via automated brachial blood pressure (including systolic (SBP), diastolic (DBP), and mean arterial pressure (MAP))
Body composition Baseline (pre-training) vs. week 6 (post-training) Assessed via dual-energy X-ray absorptiometry (DXA); including total and regional lean and fat mass. Assessed via height and weight measurements to determine BMI.
Brachial artery vascular function acutely post-exercise Acutely pre-exercise vs. post-exercise in week 1 of training Assessed via brachial artery flow mediated dilation (FMD) following a single bout of exercise in week 1 of each training group
Trial Locations
- Locations (1)
University of Guelph
🇨🇦Guelph, Ontario, Canada