The recreational athlete's heart: sex-specific three-dimensional echocardiographic reference values in relation to VO₂peak.

AIMS: This cross-sectional study aimed to quantify fitness-specific three-dimensional echocardiographic (3DE) reference values categorized by V̇O2peak to characterize the 'recreational athlete's heart' and its sex-specific adaptations across different fitness levels. Furthermore, sex-specific association with V̇O2peak was analysed.

METHODS AND

RESULTS

A total of 291 healthy participants (mean ± SD age: 27 ± 4 years; 44% female) regularly engaging in physical activity were included. Echocardiography was performed with Philips EPIQCVx ultrasound systems to assess 3DE left ventricular (LV), right ventricular (RV), and left atrial (LA) volumes, functional measures, LV mass, and ratios. Cardio-pulmonary exercise testing assessed V̇O2peak (females: 48 ± 6, males: 54 ± 8 mL/min/kg), stratifying participants into three fitness groups: low (L), moderate (M), and high (H) exercise capacity. Both sexes showed increases in 3DE end-diastolic volume with fitness [LVEDV/m², median (10th-90th percentile)]: females: L 73 (61-83), M 80 (71-90), and H 88 (80-104); males: L 82 (70-97), M 89 (76-101), and H 99 (89-114) mL/m²; with similar trends in RV and LA volumes, LV mass, and stroke volumes. The LV/RV volume (1.1 ± 0.1) and LV/LA volume (females: 2.8 ± 0.4, males: 2.9 ± 0.4) ratio and ejection fraction values did not change across fitness levels, whereas LV mass/volume ratio decreased slightly with increasing fitness without relevant sex differences [L 0.96 (0.87-1.05), M 0.91 (0.83-0.98), and H 0.87 (0.80-0.93) g/mL].

CONCLUSION

This study establishes sex- and fitness-specific 3DE reference values categorized by V̇O2peak, characterizing the recreational athlete's heart. The V̇O₂peak-associated enlargement was sex-independent; however, at a given V̇O₂peak, men exhibited greater remodelling than women. These results bridge the gap between untrained and elite athletes' hearts and may enhance 3DE evaluation of recreational athletes.