Aerobic Interval and Moderate Continuous Exercise Training on Ventricular Functions
- Conditions
- High Intensity Interval TrainingHealthyExercise Training
- Interventions
- Behavioral: High intensity-interval training (HIIT)Behavioral: Moderate intensity-continuous (MICT)
- Registration Number
- NCT04815460
- Lead Sponsor
- Chang Gung Memorial Hospital
- 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.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- Male
- Target Recruitment
- 54
- Having a sedentary lifestyle (without regular exercise, exercise frequency ≤ once weekly, duration < 20 min).
- Exposed to high altitudes (> 3000 m) for at least 1 year.
- Smoker
- Taking medications or vitamins
- Having any cardiopulmonary/hematological risk.
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description High intensity-interval training (HIIT) High intensity-interval training (HIIT) 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. Ｍoderate intensity-continuous (MCT) Moderate intensity-continuous (MICT) Subjects performed MICT (sustained 60%VO 2max) on a bicycle ergometer for 30 min/day, 5 days/week for 6 weeks.
- Primary Outcome Measures
Name Time Method The changes of right cardiac mechanics during hypoxia stress echocardiography: Strain rate 8 weeks 1. Hypoxia stress echocardiography was collected under hypoxic conditions (12% FiO2) and used two-dimensional Speckle-tracking echocardiography.
2. The resting images were acquired after the subject was placed in the aforementioned position for 10 min.
3. 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).
4. A modified apical four-chamber view was used to assess 2D-STE longitudinal and radial parameters of the RV and RA.
5. The RV strain rate was calculated using the average peak segmental values displayed by the software using a 6-segment model.The changes of right cardiac mechanics during hypoxia stress echocardiography: Strain 8 weeks 1. Hypoxia stress echocardiography was collected under hypoxic conditions (12% FiO2) and used two-dimensional Speckle-tracking echocardiography.
2. The resting images were acquired after the subject was placed in the aforementioned position for 10 min.
3. 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).
4. A modified apical four-chamber view was used to assess 2D-STE longitudinal and radial parameters of the RV and RA.
5. The RV strain was calculated using the average peak segmental values displayed by the software using a 6-segment model.
- Secondary Outcome Measures
Name Time Method Tricuspid annular plane systolic excursion (TAPSE) 8 weeks Tricuspid annular plane systolic excursion (TAPSE) measures the longitudinal excursion of the tricuspid annulus in one dimension, which was measured by M-mode.
Cardiopulmonary fitness 8 weeks 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).
The cavity diameters of RV 8 weeks 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.
Pulmonary vascular resistance (PVR) 8 weeks Pulmonary vascular resistance (PVR) was calculated using the formula PVR = (\[tricuspid regurgitation velocity/RVOT VTI\] × 10 + 0.16)
1. Tricuspid regurgitation velocity: Doppler imaging was used to measure peak tricuspid regurgitation velocities in systolic phase.
2. 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)RV diastolic function 8 weeks Doppler imaging was used to measure peak tricuspid annular (E') and flow velocities (E) in early diastole.
Trial Locations
- Locations (1)
Chang Gung University
🇨🇳Taoyuan, Taiwan