Valutazione degli aggiustamenti cardiocircolatori nel motociclismo classe enduro

Hemodynamic parameters, such as Cardiac Output (CO) and Stroke Volume (SV), have never been studied in motorcycle racing. Probably because the measurement of these variables is hampered by difficulties related to the particular environment of motorcycle performance, which can be considered an extreme condition. Moreover, these parameters need the availability of a non-­‐‑invasive and reliable portable cardiovascular measurement systems. Indeed, the only data available are about Heart Rate (HR), which increases to about 90-­‐‑95% of maximum, despite the supposed low energy requirements of motorcycle riding. The aim of this study was to measure hemodynamics enduro -­‐‑ motorcycling pilots during real motorcycle race by means of portable impedance cardiograph. Fifteen male elite motorcycle riders performing regional and national competitions on enduro motorcycles were studied. Hemodynamics was assessed by means of a portable impedance cardiograph (New Core, 2C Technologies Inc., Cagliari, Italy). Data were collected at rest, throughout 10 minutes of motorcycle race at maximum speed possible and during passive recovery. Also the blood lactate was measured at rest and after motorcycle race. The comparison between rest and exercise showed a significant increase in hemodynamic parameters. In detail, increments in both HR and SV were observed, thereby leading to a CO elevation. Systemic Vascular Resistance (SVR) showed a significant reduction, while there was an increase in systolic (SV/VET) and diastolic (SV/DT) flow index. Blood lactate significantly increase after exercise. All parameters at recovery returned to rest levels, with the exception of HR and SV/VET. Data obtained show that enduro motorcycle riding leads to significant increments in both HR and SV. While the former fact was already known, the latter is a new finding of the present investigation. The significant CO response can be the consequence of a substantial increase in cardiac contractility which can be ascribed to a sympathetic activation, as testified by the contemporary increase in HR. It is possible to speculate that the heavy muscular work of the upper and lower limbs activates the exercise pressor reflex, thereby causing sympathetic activation.