Aerobic Interval and Moderate Continuous Exercise Training on Ventricular Functions

Study Overview
=================
Brief Summary
-----------------
Hypoxic exposure increases right ventricular (RV) afterload by triggering pulmonary hypertension, with consequent effects on the structure and function of the RV. Improved myocardial contractility is a critical circulatory adaptation to exercise training. However, the types of exercise that enhance right cardiac mechanics during hypoxic stress have not yet been identified. This study investigated how high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) influence right cardiac mechanics during hypoxic exercise (HE).

Detailed Description
-----------------
Hypoxic exposure increases right ventricular (RV) afterload by triggering pulmonary hypertension, with consequent effects on the structure and function of the RV. Improved myocardial contractility is a critical circulatory adaptation to exercise training. However, the types of exercise that enhance right cardiac mechanics during hypoxic stress have not yet been identified. This study investigated how high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) influence right cardiac mechanics during hypoxic exercise (HE). The young and healthy sedentary males were randomly selected to engage in either HIIT (3-min intervals at 40% and 80% of VO2 oxygen uptake reserve) or MICT (sustained 60% of VO2 oxygen uptake reserve) for 30 min/day and 5 days/week for 6 weeks or were included in a control group (CTL) that did not engage in any exercise. Right cardiac mechanics during semiupright bicycle exercise tests under hypoxic conditions (i.e., 50 watts under 12% FiO2 for 3 min) were measured using two-dimensional speckle-tracking echocardiography. The primary outcome was the change in right cardiac mechanics during semiupright bicycle exercise under hypoxic conditions (i.e., 50 watts under 12% FiO2 for 3 min) as measured by two-dimensional speckle tracking echocardiography.

Official Title
-----------------
Aerobic Interval and Moderate Continuous Exercise Training on Ventricular Functions

Conditions
-----------------
Healthy, High Intensity Interval Training, Exercise Training

Intervention / Treatment
-----------------
* Behavioral: High intensity-interval training (HIIT)
* Behavioral: Moderate intensity-continuous (MICT)


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Having a sedentary lifestyle (without regular exercise, exercise frequency ≤ once weekly, duration < 20 min). Exclusion Criteria: Exposed to high altitudes (> 3000 m) for at least 1 year. Smoker Taking medications or vitamins Having any cardiopulmonary/hematological risk.

Ages Eligible for Study
-----------------
Minimum Age: 20 Years
Maximum Age: 30 Years

Sexes Eligible for Study
-----------------
Male

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High intensity-interval training (HIIT)<br>Subjects performed HIIT (3-min intervals at 40% and 80%VO2peak) on a bicycle ergometer for 30 min/day, 5 days/week for 6 weeks. | Behavioral: High intensity-interval training (HIIT)<br>* Subjects performed HIIT (3-min intervals at 40% and 80%VO2peak) on a bicycle ergometer for 30 min/day, 5 days/week for 6 weeks.<br>|
| Experimental: Ｍoderate intensity-continuous (MCT)<br>Subjects performed MICT (sustained 60%VO 2max) on a bicycle ergometer for 30 min/day, 5 days/week for 6 weeks. | Behavioral: Moderate intensity-continuous (MICT)<br>* Subjects performed MICT (sustained 60%VO 2max) on a bicycle ergometer for 30 min/day, 5 days/week for 6 weeks.<br>|
| No Intervention: Control group<br>Without any exercise training | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The changes of right cardiac mechanics during hypoxia stress echocardiography: Strain | Hypoxia stress echocardiography was collected under hypoxic conditions (12% FiO2) and used two-dimensional Speckle-tracking echocardiography. The resting images were acquired after the subject was placed in the aforementioned position for 10 min. The exercise images were conducted using semirecumbent cycling with a 50-Watt resistance for 3 min and acquired at the third minute of cycling to ensure that subjects had reached a steady-state HR (i.e., HR changes <10 bpm within 10 s and <110-120 bpm). A modified apical four-chamber view was used to assess 2D-STE longitudinal and radial parameters of the RV and RA. The RV strain was calculated using the average peak segmental values displayed by the software using a 6-segment model. | 8 weeks | 
| The changes of right cardiac mechanics during hypoxia stress echocardiography: Strain rate | Hypoxia stress echocardiography was collected under hypoxic conditions (12% FiO2) and used two-dimensional Speckle-tracking echocardiography. The resting images were acquired after the subject was placed in the aforementioned position for 10 min. The exercise images were conducted using semirecumbent cycling with a 50-Watt resistance for 3 min and acquired at the third minute of cycling to ensure that subjects had reached a steady-state HR (i.e., HR changes <10 bpm within 10 s and <110-120 bpm). A modified apical four-chamber view was used to assess 2D-STE longitudinal and radial parameters of the RV and RA. The RV strain rate was calculated using the average peak segmental values displayed by the software using a 6-segment model. | 8 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cardiopulmonary fitness | To assess cardiopulmonary fitness, cardiopulmonary exercise test (CPET) on a cycle ergometer was performed 4 days before and after the intervention. All subjects underwent exercise with a mask to measured oxygen consumption (VO2) breath by breath using a computer-based system (Master Screen CPX, Cardinal-health Germany). | 8 weeks | 
| The cavity diameters of RV | RV basal cavity diameter (RVD1), mid-cavity diameter (RVD2), and RV longitudinal diameter (RVD3), at end-diastole and end-systole, were evaluated in the modified apical four-chamber view. | 8 weeks | 
| Pulmonary vascular resistance (PVR) | Pulmonary vascular resistance (PVR) was calculated using the formula PVR = ([tricuspid regurgitation velocity/RVOT VTI] × 10 + 0.16) Tricuspid regurgitation velocity: Doppler imaging was used to measure peak tricuspid regurgitation velocities in systolic phase. The RV outflow tract (RVOT): obtained from a parasternal short-axis base view modified apical four-chamber view, and the flow immediately proximal to the pulmonary artery valve during systole was detected to calculate both maximal velocity and pulsed-wave blood velocity time integral (VTI) | 8 weeks | 
| RV diastolic function | Doppler imaging was used to measure peak tricuspid annular (E') and flow velocities (E) in early diastole. | 8 weeks | 
| Tricuspid annular plane systolic excursion (TAPSE) | Tricuspid annular plane systolic excursion (TAPSE) measures the longitudinal excursion of the tricuspid annulus in one dimension, which was measured by M-mode. | 8 weeks | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Stress echocardiography, Hypoxia test, Speckle-tracking echocardiography, High Intensity Interval Training