In this work we present a mathematical model for the coupling of cardiovascular system and metabolism under sport efforts. Effects such as oxygenation, heart rates, flow rates, blood pressure and mass transfer to tissues will be considered. A special attention will be payed to the modelling of the regulatory mechanisms (baroreflex and chemoreflex effectors) affecting the heart and the peripheral circulation. We aim at extending the existing models to describe metabolism, hemodynamics and mass transport during exercise, providing a framework to understand their mutual interactions. Numerical issues are presented for different workloads, and a quantitative analysis of dynamic aerobic exercise is discussed.