Strength training improves heart function, collagen and strength in rats with heart failure

Area of Science:

• Cardiovascular Physiology
• Exercise Science
• Cardiac Pathophysiology

Background:

• Myocardial infarction (MI) often leads to cardiac remodeling, heart failure, and reduced quality of life.
• Physical exercise is a recognized non-pharmacological therapy for cardiovascular diseases.
• The specific effects of strength training (ST) on cardiac remodeling post-MI require further investigation.

Purpose of the Study:

• To investigate the role of a linear block ST protocol in a rat model of MI.
• To assess the impact of ST on structural and functional cardiac remodeling after MI.

Main Methods:

• Adult male rats underwent MI induction or sham surgery, followed by 12 weeks of a structured, progressive ST program.
• Echocardiography, hemodynamic assessment, and histology were used to evaluate cardiac structure and function.
• Isolated cardiac muscle contractility was measured in response to various stimuli.

Main Results:

• Strength training improved performance and reduced cardiac hypertrophy and pulmonary congestion in infarcted rats.
• ST partially prevented cardiac dilation and ventricular dysfunction without altering MI size.
• Histological analysis showed reduced interstitial fibrosis, and isolated cardiac muscles exhibited improved contractility.

Conclusions:

• Strength training in infarcted rats enhances mass-carrying capacity and attenuates cardiac remodeling and pulmonary congestion.
• Improved cardiac function post-ST is partly attributed to enhanced myocardial contractility.
• ST offers a potential non-pharmacological intervention to improve outcomes after myocardial infarction.