A fitness machine operable by a user. The fitness machine has a base and a mobile portion that moves relative to the base during operation. A resilient body resists movement of the mobile portion towards the base in a height direction. The resilient body has a length defined in a length direction that is perpendicular to the height direction. The length of the resilient body increases when the mobile portion moves towards the base. An end stop is operable to prevent the length of the resilient body from increasing beyond a set maximum. The end stop is moveable to adjust the set maximum for the length of the resilient body, where a resistance provided by the resilient body to resist movement of the mobile portion towards the base is unaffected by moving the end stop when the length of the resilient member is less than the set maximum.