Myocardial Adaptations to Competitive Swim Training

Area of Science:

• Cardiovascular Physiology
• Sports Science
• Exercise Physiology

Background:

• Swim training involves unique cardiac volume loading due to water immersion.
• Prospective data on cardiac responses to swim training are limited.
• Understanding myocardial adaptations is crucial for competitive athletes.

Purpose of the Study:

• To investigate myocardial adaptations in competitive swimmers.
• To establish a causal link between swim training and left ventricular (LV) remodeling.
• To define cardiac responses to intensified swim training.

Main Methods:

• Studied collegiate swimmers before and after 90 days of intensified training.
• Utilized transthoracic echocardiography for LV structural and functional analysis.
• Assessed LV adaptations at rest and during isometric handgrip testing (IHGT) afterload challenge.

Main Results:

• Swim training induced eccentric LV remodeling (chamber dilation > wall thickening).
• Observed enhanced resting LV systolic (twist) and diastolic function.
• Post-training, athletes showed impaired systolic twist during IHGT, but preserved stroke volume due to LV dilation and improved diastolic function.

Conclusions:

• Swim training stimulates eccentric LV remodeling and augments systolic twist and diastolic relaxation.
• Volume-mediated cardiac remodeling may increase susceptibility to acute afterload.
• Further research is needed on functional changes, performance translation, and relevance to heart disease.