Cardiac dimensions in athletes in relation to variations in their training program

Area of Science:

• Sports Medicine
• Cardiology
• Physiology

Background:

• Endurance athletes often display cardiac adaptations.
• The impact of training seasonality on these adaptations requires further investigation.

Purpose of the Study:

• To compare cardiac dimensions and left ventricular hypertrophy (LVH) in male long-distance runners (LDR) and cycle racers (CR) across different training seasons.
• To assess maximal aerobic performance in relation to training phases.

Main Methods:

• Echocardiography was used to measure cardiac dimensions in athletes and control subjects (CS) across four training seasons.
• Electrocardiography assessed left ventricular hypertrophy (LVH).
• Maximal aerobic performance was determined using a bicycle ergometer.

Main Results:

• Athletes consistently showed significantly greater left ventricular mass, interventricular septum thickness, left ventricular posterior wall thickness, and left ventricular internal diameter than CS.
• Electrocardiographic findings confirmed LVH in athletes.
• No significant cardiac dimension differences were found between the four training seasons, despite training variations.
• Maximal aerobic performance varied by season, with higher workloads in competitive phases for LDR and lower values during rest for CR.

Conclusions:

• Athletes exhibit persistent cardiac adaptations (LVH) regardless of training season.
• Cardiac dimension adaptation to training load variations is a slow process.
• Performance metrics fluctuate seasonally, indicating a lag in cardiac response to training intensity changes.