ABSTRACT
Both haemodynamics and left ventricular (LV) contractility are significantly affected by body posture[1, 2, 3]. Due to the more favourable filling conditions in the supine posture, supine stroke volume (SV) and cardiac output (CO) at rest are significantly greater than in the seated posture[1, 2, 3, 4]. At the onset of exercise SV, CO and contractility rise significantly, in particular in the seated posture[2, 3]. However, SV and CO in the seated posture attain the supine levels, if ever, only at high intensity or maximal exercise[1, 3]. Observations in sedentary and highly trained adult men[1] suggest that physical training may attenuate the differences in cardiovascular capacity between supine and seated posture both at rest and during exercise. The purpose of this study was to evaluate this aspect of the effect of physical training in prepubertal boys by comparing cardiovascular adaptation at rest and during exercise in supine and seated posture before and after physical training.
