# Cardiac function and autonomic cardiac function during a multi-stage cycling event: a brief report

## TL;DR

A study on a trained cyclist found improved heart function during a long cycling event, but no clear link to autonomic heart control or cardiac fatigue.

## Contribution

This study provides new insights into cardiac and autonomic responses during prolonged cycling without observing cardiac fatigue.

## Key findings

- Systolic function of both left and right ventricles improved progressively during the cycling event.
- Cardiac autonomic function showed sympathetic-parasympathetic imbalance but no significant correlation with cardiac function.
- No signs of exercise-induced cardiac fatigue were observed in the athlete.

## Abstract

Prolonged and repeated exercise performed during an ultra-endurance event can induce general and cardiac fatigue known as exercise-induced cardiac fatigue. Our objective was to find a possible correlation between the cardiac function and the autonomic cardiac function.

During a multistage ultra-endurance event, a female well-trained cyclist underwent daily rest echocardiography and heart rate variability measurements to assess the cardiac function and the cardiac autonomic function.

The athlete completed 3,345 km at 65% of her maximum heart rate and 39% of her maximum aerobic power. A progressive improvement of the systolic function for both the left ventricle and the right ventricle was observed during the event.

Alterations were observed on the cardiac autonomic function with an imbalance between sympathetic and parasympathetic, but there was no sign of a significant correlation between the cardiac function and the autonomic cardiac function and no signs of cardiac fatigue either. Further analysis should be performed on a larger sample to confirm the obtained results.