Energy-saving body-building self-propelled four-wheeler

The energy-saving body-building self-propelled four-wheeler comprises a vehicle body with a bottom plate, a seat mechanism, a paddling mechanism and a pedal assembly, the seat mechanism comprises a supporting rod extending in the vertical direction and is provided with a connecting end, an installing end and a seat body detachably installed at the installing end, the rear side of the connecting end is rotatably installed on the bottom plate, and the back side of the connecting end is rotatably installed on the pedal assembly. The supporting rod is arranged on the base plate, so that the supporting rod has a first state of rotating to be horizontal with the base plate and a second state of being locked and fixed on the base plate in the vertical direction, a foot supporting plate is arranged on the side surface of the supporting rod to support the sole of a user in the first state, and the seat body is slidably mounted on the supporting rod in the first state; the sliding mechanism comprises a resistance struc