Pedal assisted bicycle comprising: - a first and second wheels (5"), - at least one mechanical brake applied to one of the first and second (5") wheels and a brake command for actuating said mechanical brake; - a pedaling assembly mechanically decoupled from said first and second wheels (5"), by which a user can supply a pedaling power (Wped), - an electric motor mechanically coupled to at least one of said first and second wheels (5") capable of taking a motor power (Wmot), - a generator device adapted to generate a generator device electric power (Wgen) from said pedaling power (Wped), arranged in an energy exchange relationship with the pedaling assembly and the electric motor; - an energy storage device arranged in an energy exchange relationship with said electric motor and generator device, - a control system comprising a module for controlling the power (Wgen) required to the generator device to be supplied to the electric motor and/or to the storage device, characterized in that it comprises a heartbeat sensor adapted to generate a signal representing the heartbeat and a sensor for detecting the braking intent of the user, associated to the brake command, adapted to generate a signal representing a braking intent of the user, and said control system being operatively connected to the braking intent detecting sensor and being configured for determining the generator device required power (Wgen) as a function also of said braking intent representing signal, and in that said module for controlling the electric power required to the generator device (Wgen) is operatively connected to the heartbeat sensor and is configured in order to: - determine the electric power required to the generator device (Wgen) as a function of said signal representing the heartbeat in the absence of such signal representing the bicycle braking intent; - keep the electric power required to the generator device (Wgen) equal to a minimum predetermined value (Wgen*) in presence of said signal representing the bicycle braking intent, so that the user notices a minimal resistance to pedal. - a first and second wheels (5"), - at least one mechanical brake applied to one of the first and second (5") wheels and a brake command for actuating said mechanical brake; - a pedaling assembly mechanically decoupled from said first and second wheels (5"), by which a user can supply a pedaling power (Wped), - an electric motor mechanically coupled to at least one of said first and second wheels (5") capable of taking a motor power (Wmot), - a generator device adapted to generate a generator device electric power (Wgen) from said pedaling power (Wped), arranged in an energy exchange relationship with the pedaling assembly and the electric motor; - an energy storage device arranged in an energy exchange relationship with said electric motor and generator device, - a control system comprising a module for controlling the power (Wgen) required to the generator device to be supplied to the electric motor and/or to the storage device, characterized in that it comprises a heartbeat sensor adapted to generate a signal representing the heartbeat and a sensor for detecting the braking intent of the user, associated to the brake command, adapted to generate a signal representing a braking intent of the user, and said control system being operatively connected to the braking intent detecting sensor and being configured for determining the generator device required power (Wgen) as a function also of said braking intent representing signal, and in that said module for controlling the electric power required to the generator device (Wgen) is operatively connected to the heartbeat sensor and is configured in order to: - determine the electric power required to the generator device (Wgen) as a function of said signal representing the heartbeat in the absence of such signal representing the bicycle braking intent; - keep the electric power required to the generator device (Wgen) equal to a minimum predetermined value (Wgen*) in presence of said signal representing the bicycle braking intent, so that the user notices a minimal resistance to pedal. - determine the electric power required to the generator device (Wgen) as a function of said signal representing the heartbeat in the absence of such signal representing the bicycle braking intent; - keep the electric power required to the generator device (Wgen) equal to a minimum predetermined value (Wgen*) in presence of said signal representing the bicycle braking intent, so that the user notices a minimal resistance to pedal.