Adjusting group (1) for adjusting the position of a user-interface (2) of a gymnastic machine (100) relative to a respective frame (102) thereof; a sliding coupling unit (120) being associated with the user-interface (2) to define a first path (L) for adjusting the position of the user-interface (2) with respect to the frame (102); a blocking device (130) being provided in combination with the coupling unit (120) to fix the user-interface (2) in any position along the first path (L); the coupling unit (120) comprising a guide (122) associated with the frame (102) and a slide (124) associated with the user-interface (2) and coupled to the guide (122) in a sliding fashion along respective first coupling surface (1220) and second coupling surface (1240).