Interval and continuous exercise enhances aerobic capacity and hemodynamic function in CHF rats.

Area of Science:

• Cardiology
• Exercise Physiology
• Animal Models

Background:

• Chronic heart failure (CHF) in rats leads to impaired hemodynamic parameters, cardiac remodeling, and reduced exercise capacity.
• Aerobic exercise training is a recognized intervention for cardiovascular disease, but optimal training protocols for CHF remain under investigation.

Purpose of the Study:

• To compare the effects of continuous aerobic training (ACT) versus aerobic interval training (AIT) on hemodynamic function, cardiac structure, and maximal exercise capacity (MEC) in a rat model of CHF.

Main Methods:

• Male Wistar rats underwent myocardial infarction (MI) surgery to induce CHF.
• Five weeks post-MI, rats were assigned to sedentary (CHF-Sed), ACT, or AIT groups for 8 weeks of treadmill exercise.
• Training protocols involved specific durations, intensities, and interval structures for ACT and AIT.

Main Results:

• Both ACT and AIT reduced left ventricular end-diastolic pressure, left ventricular mass/body mass ratio, and collagen volume fraction compared to CHF-Sed.
• Systolic ventricular pressure and +dP/dtmax were elevated in trained groups, with ACT showing higher +dP/dtmax than AIT.
• Both training groups improved MEC, but AIT demonstrated superior improvements in maximal exercise capacity.

Conclusions:

• Aerobic exercise, both continuous and interval, is beneficial for improving cardiac function, remodeling, and physical capacity in CHF rats.
• Aerobic interval training may be a superior strategy for maximizing exercise capacity improvements in CHF, warranting further research into optimal exercise parameters.