Cardiovascular adaptation to training load in endurance athletes: a longitudinal study

Area of Science:

• Cardiology
• Sports Medicine
• Exercise Physiology

Background:

• Previous studies on exercise-induced cardiac remodelling relied on self-reported data.
• Objective quantification of exercise is needed to accurately assess its impact on the heart.

Purpose of the Study:

• To objectively quantify exercise duration and intensity in athletes using heart rate (HR) monitors.
• To correlate these objective exercise metrics with cardiac magnetic resonance imaging (CMR) findings.

Main Methods:

• Included young (16-23 yrs) and middle-aged (45-70 yrs) male endurance athletes (n=151).
• Utilized chest-worn HR monitors to record training sessions over 3 months.
• Analyzed training duration, session count, intensity (HR zones, Edwards training impulse), and CMR-measured cardiac dimensions.

Main Results:

• Younger athletes trained more than older athletes in both duration and intensity.
• Training duration and Edwards training impulse correlated with cardiac dimensions.
• Training duration, particularly in lower HR zones, was a stronger determinant of cardiac remodelling than intensity.

Conclusions:

• Objective exercise quantification reveals exercise duration as a primary determinant of cardiac remodelling.
• Left/right ventricular volumes are influenced by total exercise duration, independent of training intensity.
• Traditional self-reported exercise data may not capture these crucial relationships.