Evaluation of the Left Ventricular Myocardium Using Layer-Specific Strain Analysis in Adolescent Athletes Performing High-Intensity Interval Training.

High-intensity interval training (HIIT) has been demonstrated to be an efficient way of improving physical performance in adolescent athletes compared to conventional training modalities. The objective of this study was to evaluate the impact of HIIT on the myocardial function of adolescent athletes, specifically focusing on left ventricular (LV) function, using conventional echocardiography and layer-specific strain (LSS) analysis. A total of 19 male adolescent athletes (with mean age of 16.83 ± 1.29 years) participating in various football clubs were recruited for this study. During the course of 8 weeks, these adolescent male athletes engaged in HIIT program centered around running. Upon completion of HIIT program, a treadmill exercise test was conducted. Subsequently, conventional and LSS echocardiography were conducted to acquire the evaluation of LV myocardial function. Interventricular septum thickness and ventricular mass index were significantly increased post high-intensity interval training (p < 0.005). After the HIIT, the treadmill exercise test demonstrated a significant increase in test duration and metabolic equivalent compared to the pre-training values (p < 0.005). Post high-intensity interval training, LSS analysis revealed significantly improved LV circumferential strain values in the basal and mid-segments of the left ventricle when compared to the pre-training measurements (p < 0.005). The implementation of high-intensity interval training led to an enhancement of circumferential LSS in the LV, indicating a favorable physiological adaptation and improved efficiency of the myocardium.