The Relationship Between Exercise Frequency, Intensity, and Restoration of Cardiometabolic Health

Overweight or Obesity Clinical Trial

Official title:

The Relationship Between Exercise Frequency, Intensity, and Restoration of Cardiometabolic Health

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03376685
• Other study ID #: 17-08-008
• Status: Completed
• Phase: N/A
• Start date: May 30, 2018
• Est. completion date: November 18, 2019

Study information

• Verified date: April 2020
• Source: University of Guelph
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

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 information / eligibility

• Status: Completed
• Enrollment: 23
• Est. completion date: November 18, 2019
• Est. primary completion date: November 18, 2019
• Accepts healthy volunteers: No
• Gender: Male
• Age group: 18 Years to 70 Years

Eligibility

Inclusion Criteria:

• 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+)

Exclusion Criteria:

• Prescribed with glucose lowering medications

• Smoker

• Not cleared for physical activity

Related Conditions & MeSH terms

• Overweight
• Overweight or Obesity

Intervention

Behavioral:
• Endurance Exercise Training (END)
Physical activity will be conducted on cycle ergometers under supervision. Participants will exercise 5 days a week for 30 minutes (Week 1-2); 35 minutes (Weeks 3-4); or 40 minutes (Weeks 5-6) at 60% VO2 peak.
• Sprint Exercise Training (SIT)
Physical activity will be conducted on cycle ergometers under supervision. Participants will exercise 3 days a week involving a 3-minute warm-up, followed up 4 repetitions (Week 1-2); 5 repetitions (Weeks 3-4); or 6 (Weeks 5-6) repetitions of 30 seconds at a maximal intensity with 2 minutes' rest in between. Exercise will conclude with a 2-minute cool-down.

Locations

Country	Name	City	State
Canada	University of Guelph	Guelph	Ontario

Sponsors (1)

Lead Sponsor	Collaborator
University of Guelph

Country where clinical trial is conducted

Canada, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Cardiorespiratory fitness	Assessed via VO2 peak test, to determine the change in cardiorespiratory fitness following 6-weeks of exercise training	Baseline (pre-training) vs. week 6 (post-training)
Primary	Free-living glycemic regulation	Assessed via continuous glucose monitoring (CGM), to determine the change in free-living glycemic regulation following 6-weeks of exercise training	Baseline (pre-training) vs. week 6 (post-training)
Primary	Glucose tolerance	Assessed via an oral glucose tolerance test (OGTT) to determine changes in standardized glycemic regulation following 6-weeks of exercise training	Baseline (pre-training) vs. week 6 (post-training)
Secondary	Blood lipids	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	Baseline (pre-training) vs. week 6 (post-training)
Secondary	HbA1C	Change in HbA1C assessed via fasted venous blood sampling, following 6-weeks of exercise training	Baseline (pre-training) vs. week 6 (post-training)
Secondary	Post-prandial blood lipids	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	Baseline (pre-training) vs. week 6 (post-training)
Secondary	Blood pressure	Assessed via automated brachial blood pressure (including systolic (SBP), diastolic (DBP), and mean arterial pressure (MAP))	Baseline (pre-training) vs. week 6 (post-training)
Secondary	Body composition	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.	Baseline (pre-training) vs. week 6 (post-training)
Secondary	Arterial stiffness	Assessed via carotid-femoral pulse wave velocity (PWV)	Baseline (pre-training) vs. week 6 (post-training)
Secondary	Arterial stiffness acutely post-exercise	Assessed via carotid-femoral pulse wave velocity (PWV) following a single bout of exercise in week 1 of each group	Acutely pre-exercise vs. post-exercise in week 1 of training
Secondary	Brachial artery vascular function	Assessed via brachial artery flow mediated dilation (FMD) following 6-weeks of exercise training	Baseline (pre-training) vs. week 6 (post-training)
Secondary	Brachial artery vascular function acutely post-exercise	Assessed via brachial artery flow mediated dilation (FMD) following a single bout of exercise in week 1 of each training group	Acutely pre-exercise vs. post-exercise in week 1 of training
Secondary	Daily sedentary/active time	Assessed via accelerometer	Baseline (pre-training), week 1 (of training), week 6 (post-training)
Secondary	Free-living glycemic regulation during the first week of exercise training	Assessed via continuous glucose monitoring (CGM)	Baseline (pre-training) vs. week 1 (of training)