The present invention concerns a support frame for a gymnastic apparatus, particularly for a cycling simulation device, comprising a base, and a first arm hinged with said base and a second arm hinged with said base, so that said first and second arm can assume a closed position and an open position, rotating with respect to said base, characterized in that said support frame comprises an articulation member articulated with said base and said first and second arm such that the rotation of one of said first or second arm relatively to said base causes a rotational translation of said articulation member and the rotation of the other arm with respect to said base, causing the passage from said closed position to said open position or vice versa.