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

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.

Study Overview

• Status: Completed
• Conditions: Overweight or Obesity
• Intervention / Treatment: Behavioral: Endurance Exercise Training (END); Behavioral: Sprint Exercise Training (SIT)

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.

• Study Type: Interventional
• Enrollment (Actual): 23
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Guelph, Ontario, Canada, N1G 2W1
      • University of Guelph

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 70 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Male

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Endurance Exercise Training (END); This group is performing END training for 6 weeks in duration. Intervention: Behavioral: Endurance Exercise Training (END)	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.
Experimental: Sprint Exercise Training (SIT); This group is performing SIT training for 6 weeks in duration. Intervention: Behavioral: Sprint Exercise Training (SIT)	Behavioral: 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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)
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)
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 Outcome Measures

Outcome Measure	Measure Description	Time Frame
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)
HbA1C	Change in HbA1C assessed via fasted venous blood sampling, following 6-weeks of exercise training	Baseline (pre-training) vs. week 6 (post-training)
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)
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)
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)
Arterial stiffness	Assessed via carotid-femoral pulse wave velocity (PWV)	Baseline (pre-training) vs. week 6 (post-training)
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
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)
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
Daily sedentary/active time	Assessed via accelerometer	Baseline (pre-training), week 1 (of training), week 6 (post-training)
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)

Collaborators and Investigators

• Sponsor: University of Guelph
• Investigators: Principal Investigator: Jamie Burr, PhD, University of Guelph; Principal Investigator: Graham Holloway, PhD, University of Guelph

Publications and helpful links

General Publications

• Petrick HL, King TJ, Pignanelli C, Vanderlinde TE, Cohen JN, Holloway GP, Burr JF. Endurance and Sprint Training Improve Glycemia and V O2peak but only Frequent Endurance Benefits Blood Pressure and Lipidemia. Med Sci Sports Exerc. 2021 Jun 1;53(6):1194-1205. doi: 10.1249/MSS.0000000000002582.

Study record dates

Study Major Dates

• Study Start (Actual): May 30, 2018
• Primary Completion (Actual): November 18, 2019
• Study Completion (Actual): November 18, 2019

Study Registration Dates

• First Submitted: December 6, 2017
• First Submitted That Met QC Criteria: December 12, 2017
• First Posted (Actual): December 18, 2017

Study Record Updates

• Last Update Posted (Actual): April 29, 2020
• Last Update Submitted That Met QC Criteria: April 27, 2020
• Last Verified: April 1, 2020

More Information

Terms related to this study

• Keywords: Endurance training; Cardiovascular health; Sprint interval training; Glycemic regulation; Lipid homeostasis
• Additional Relevant MeSH Terms: Body Weight; Overweight
• Other Study ID Numbers: 17-08-008

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No