Increased active phase atrial contraction is related to marathon runner performance

Area of Science:

• Cardiology
• Sports Physiology
• Exercise Science

Background:

• Left atrial (LA) contraction is crucial for efficient left ventricular (LV) filling, especially during physical exertion.
• Understanding the adaptive cardiovascular changes in elite athletes, particularly concerning atrial function, is vital for optimizing training and performance.

Purpose of the Study:

• To investigate the relationship between left atrial (LA) contraction and exercise capacity in trained marathon runners.
• To evaluate how marathon running affects LA contractile function (LASa) and its correlation with maximal aerobic capacity (VO2 max).

Main Methods:

• Sixteen male marathon runners were divided into high-volume (>100 km/week) and lower-volume training groups.
• Cardiopulmonary exercise testing for VO2 max and transthoracic echocardiography to assess LA contractile function (LASa) were performed pre- and post-marathon.
• LASa change was calculated as pre-marathon LASa minus immediate post-marathon LASa.

Main Results:

• The highly trained group exhibited larger LA volume index, LV mass index, and higher VO2 max compared to the less trained group.
• A significant increase in LASa was observed post-marathon, with a markedly greater augmentation in the highly trained athletes.
• Increased post-marathon LASa positively correlated with pre-marathon VO2 max and inversely with marathon completion time.

Conclusions:

• Intensive training in athletes is associated with enhanced LV mass and LA dimensions.
• Marathon running induces a significant increase in LA contraction, particularly pronounced in highly trained individuals.
• The augmented LA contraction post-marathon is directly related to maximal aerobic capacity and overall race performance.