The Relationship Between Exercise Frequency, Intensity, and Restoration of Cardiometabolic Health
Phase: NA
Conditions: Overweight or Obesity
Sponsor: University of Guelph

STUDY PROTOCOL 
The Relationship Between Exercise Frequency, Intensity, and Restoration of 
Cardiometabolic Health 
NCT #03376685 
Last updated: November 5, 2018 (Most recent institutional ethics approval of renewal) 
Principal Investigators: Dr. Jamie Burr, PhD; Dr. Graham Holloway, PhD 
Affiliation: University of Guelph 
 
1.0 INTRODUCTION 
1.1 Background 
Involvement in regular physical activity is well established to reduce the risk of many clinically 
relevant risk factors, including hypertension, dyslipidemia, obesity, and hyperglycemia. Traditional 
physical activity recommendations suggest 150 minutes of moderate-intensity continuous 
endurance (END) exercise dispersed over 5 days per week is sufficient to improve physical fitness 
in adults (1). 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 glycemic regulation compared to classical END exercise, particularly when protocols 
are volume-matched (2). However, as END is conducive to daily sessions not feasible of SIT 
training, current literature volume-matching these approaches have restricted END to shorter and 
less frequency bouts than guidelines indicate is optimal. Furthermore, improvements in many 
clinically relevant risk factors are transient in nature (3). Therefore, the ability of END and SIT to 
improve these health parameters, when performed as per general practice (i.e. high-frequency 
END, low-frequency SIT) remains unknown. 
1.2 Objectives 
The aim of this study is to determine the ability of 6-week high-frequency END or low-frequency 
SIT exercise training to reduce clinically relevant cardiometabolic risk factors in overweight/obese 
males.  
1.3 Hypothesis 
It is hypothesized that END of greater frequency will markedly improve cardiometabolic health, 
while lower frequency SIT will not. 
 
2.0 STUDY DESIGN AND METHODS 
This study is a 6-week parallel exercise intervention trial. The temporal sequence of events in this 
study is displayed below in Figure 1: Experimental Timeline. Further details are provided in the 
subsequent text.  
 
 
 
CGM
Visit 1
DEXA
BP
PWV
FMD
OGTT
Visit 2
Blood analysis
OFTT
Visit 3
VO2max
Visit 2
DEXA
BP
PWV
FMD
OGTT
Visit 3
Blood analysis
OFTT
Pre-training
Week 1
Week 2
Week 3
Week 4
Week 5
Week 6
Post-training
CGM
Visit 1
VO2max
>48hrs
48hrs
24hrs
END (5d·wk-1)
SIT (3d·wk-1)

STUDY PROTOCOL 
 
2
Figure 1: Experimental Timeline 
 
2.1 Participant Characteristics 
2.1.1 Inclusion Criteria 
• 
Male 
• 
Aged 18-70 years 
• 
Body mass index > 25 kg/m2 (classified as overweight or obese) 
• 
Physically inactive (< 100 minutes of moderate physical activity per week) 
• 
Willingness and physical ability to begin a vigorous exercise regime 
• 
Approval for exercise via physical activity readiness questionnaire (PARQ+) 
 
2.1.2 Exclusion Criteria 
• 
Smoker 
• 
Prescribed with glucose lowering medication 
• 
Not cleared for physical activity 
 
2.2 Pre-Screening Assessments 
Participants will report to the laboratory at the University of Guelph to be informed of study details, 
any possible risks associated with the study, and provide written informed consent (approved by 
University of Guelph Human Research Ethics Board REB #17-08-008). To determine eligibility for 
this study, the following will be assessed: 
 
• 
Health Questionnaire/ PARQ+ 
• 
Resting Blood Pressure 
• 
Height and Weight 
 
2.3 Pre-Exercise Testing 
The pre-training testing will be conducted over three separate days, each of which will be 
following a 12-hour overnight fast, and having refrained from exercise or caffeine for 24-hours. 
 
2.3.1 Pre-Exercise Visit 1: 
• 
Dual-Energy X-Ray Absorptiometry (DXA): Lean body mass, body fat percentages (total 
and regional), and body mass index will be assessed via a whole-body DXA scan. 
• 
Pulse Wave Velocity (PWV): Arterial stiffness will be assessed via central PWV between 
carotid artery and femoral artery sites. 
• 
Flow Mediated Dilation (FMD): Vascular function of the brachial artery will be assessed 
using FMD procedures of forearm occlusion and re-perfusion. 
• 
Continuous Glucose Monitor (CGM) Sensor Insertion: This device (FreeStyle Libre Pro, 
Abbott Diabetes) will remain inserted for 14 days in duration at the beginning of this study to 
assess free-living blood glucose levels at 15-minute intervals. An additional CGM period will 
occur during the final two weeks of exercise training (14 days in duration).  
• 
Accelerometer Physical Activity Monitoring: This device will be administered to 
participants for 3 days at baseline, 3 days during the initial week of exercise, and 3 days during 
the final week of training to assess sedentary/active time during the day.  
• 
Oral Glucose Tolerance Test (OGTT): The 2-hour post-prandial glucose response will be 
assessed via capillary finger-stick following the consumption of a 75g glucose beverage. 
 
 
2.3.2 Pre-Exercise Visit 2: 

STUDY PROTOCOL 
 
3
• 
Fasting Blood Lipid Profile: Venous blood lipid analysis will include high-density lipoprotein 
(HDL), low-density lipoprotein (LDL), high-sensitivity C-reactive protein (hs-CRP), free fatty 
acids (FFA), total cholesterol, serum triglycerides (TAG), and non-HDL cholesterol, 
cholesterol/HDL ratio. HbA1C will also be assessed as an indication of glycemic homeostasis. 
• 
Oral Fat Tolerance Test (OFTT): Consumption of a 90g lipid beverage will be followed by 
the assessment of serum TAG and free fatty acids (FFA) each subsequent hour for a total of 
five (5) hours in duration. Blood draws will occur through an intravenous catheter line. 
• 
Diet Log: Participants will record their dietary intake for three (3) days following this visit. 
Three (3) additional dietary recording periods will occur throughout the study, which will 
additionally encompass a three (3) day recording period. 
 
2.3.3 Pre-Exercise Visit 3: 
This assessment will occur as the first exercise bout. 
• 
VO2 Peak Assessment: Maximal aerobic capacity will be assessed during an exercise test 
to exhaustion conducted on a cycle ergometer. 
 
 
2.4 Exercise Training Protocol 
Participants will be randomized to one of two training interventions in a parallel design. The total 
training intervention will be 6 weeks in duration with progression throughout in terms of exercise 
bout duration. The intervention groups are listed below. 
 
2.4.1 Endurance (END) Training (Table 1) 
 
END (5d/wk) 
  
Week 1 
Weeks 2-4 
Weeks 5-6 
Protocol 
M, T 
W, Th, F 
M-F 
M-F 
30 min  
(60% VO2peak) 
30 min  
(60% VO2peak) 
35 min 
(60% VO2peak) 
40 min 
(60% VO2peak) 
Daily Time 
Commitment 
30 min 
30 min 
35 min 
40 min 
 
2.4.2 Sprint (SIT) Training (Table 2) 
SIT (3d/wk) 
  
 
Week 1 
Weeks 2-4 
Weeks 5-6 
Protocol 
3 min warm-up (50W); 2 min cool-down (50W) 
M, W 
F 
M, W, F 
M, W, F 
4 x 30 sec  
(170% Peak 
Wattage)  
/ 2 min (50W) 
4 x 30 sec 
(170% Peak 
Wattage)  
/ 2 min (50W) 
5 x 30 sec 
(170% Peak Wattage) 
/ 2 min (50W) 
6 x 30 sec 
(170% Peak 
Wattage) 
/ 2 min (50W) 
Daily Time 
Commitment 
13 min 
13 min 
15.5 min 
18 min 
 
 
 
All training will be supervised on cycle ergometers. Before each exercise bout, blood pressure 
(BP) will be measured. If within a normal range, participants will begin exercising with heart rate 

STUDY PROTOCOL 
 
4
monitored throughout. During one exercise visit in Week 1, PWV will be conducted pre-exercise, 
immediately post-exercise, 15-minutes post-exercise, and 30-minutes post-exercise to assess 
acute vascular changes. Similarly, FMD will be conducted pre-exercise, post-exercise, and 30-
minutes post-exercise.  
 
2.5 Post-Exercise Testing 
The pre-exercise tests (as explained above) will be re-assessed following the training 
intervention. The order in which these tests will occur is as follows: 
 
2.5.1 Post-Training Testing Visit 1: VO2 Peak Test 
2.5.2 Post-Training Testing Visit 2: PWV, FMD, OGTT, CGM Removal, DXA 
2.5.3 Post-Training Testing Visit 3: Blood Analysis, OFTT 
 
3.0 DATA ANALYSIS 
Additional information is provided in the attached statistical analysis plan (SAP). 
 
4.0 REFERENCES 
(1) Nelson ME, Rejeski WJ, Blair SN, Duncan PW, Judge JO, King AC, Macera CA and Castaneda-
Sceppa C (2007). Physical activity and public health in older adults: recommendation from the American 
College of Sports Medicine and the American Heart Association. Circulation. 116, 1094-1105. 
(2) Gibala MJ, Little JP, MacDonald MJ and Hawley JA (2012). Physiological adaptations to low-volume, 
high-intensity interval training in health and disease. J. Physiol. 590, 1077-1084. 
(3) Burr JF, Rowan CP, Jamnik VK and Riddell MC (2010). The role of physical activity in type 2 diabetes 
prevention: physiological and practical perspectives. Phys. Sportsmed. 38, 72-82.