A method of feeding air to an internal combustion engine having at least first and second internal cavities, including: completing the intake phase of the first combustion chamber of the first internal cavity by feeding compressed air into the first combustion chamber until a maximum volume thereof is reached; during a beginning of the compression phase of the first combustion chamber and a simultaneous beginning of the intake phase of the second combustion chamber of the second internal cavity, feeding compressed air from the first combustion chamber into the second combustion chamber; closing a communication between the first and second combustion chambers and completing the intake phase of the second combustion chamber by feeding compressed air into the second combustion chamber until a maximum volume thereof is reached.