Does submaximal supine exercise alter left ventricular volumes and ejection fraction in young endurance athletes?
Submaximal supine exercise in young endurance athletes produces small increases in left ventricular end-diastolic and stroke volumes, with similar physiological adaptations observed in both men and women.
AIM: The primary objective of the study was to measure the relative left ventricular volumes and the changes in left ventricular ejection fraction during supine position from rest to exercise in young endurance athletes. The secondary objective was to examine if there were gender differences regarding the volume reply and ejection fraction with exercise. METHOD: Sixty-five (35 female and 30 males) young healthy Swedish orienteers participated in the study. Left ventricular volume and ejection fraction changes between rest and submaximal supine bicycle exercise were measured with radionuclide ventriculography. RESULTS: The mean left ventricular end-diastolic volume increased by 13% (P 0.04 units) in 54% of the athletes from rest to exercise; 5% of the athletes showed a decrease in ejection fraction. A negative correlation was found between ejection fraction at rest and the difference in ejection fraction from rest to exercise (r = -0.38, P = 0.002). There were no gender differences in the left ventricular volume changes or ejection fraction. CONCLUSION: During submaximal supine exercise, the adjustments in cardiac volumes in endurance athletes were small. There were no gender disparities concerning the left ventricular volume reply during exercise.
Sundstedt et al. (Fri,) studied this question.