Self-propelling vehicle for exercise

A self-propelling vehicle for exercise, comprising:

• a frame assembly;
• a seat element, which is arranged on the frame assembly;
• two moving front wheels, which are arranged on two sides of the seat element;
• a drive pedal, which is connected to and drives each of the moving front wheels;
• at least one steering rear wheel, which is arranged on one side of the frame assembly opposite to the drive pedal;
• a protective cover, which is pivotally connected to a top of the steering rear wheel for steering in synchronization therewith;
• an operation assembly, which is connected to the protective cover to operate the steering rear wheel to carry out change of a moving direction, wherein the operation assembly comprises an operating member controllable by a user, at least one first transmission axle pivotally disposed in the frame assembly, a connection member fixed on one end of the first transmission axle and drivable by the operating member, and a second transmission axle, wherein one end of the second transmission axle is pivotally arranged at one side of the first transmission axle, and another end is fixed to the protective cover;
• and
• a switching assembly, which is arranged on one side of the connection member and comprises a positioning portion and an adjustment member corresponding to and engageable with the positioning portion, so as to have the second transmission axle and the first transmission axle rotating synchronously when engaging with the positioning portion and to have the second transmission axle rotating freely when disengaging from the positioning portion.