An exercise machine assembly provides a fluid-based resistance force and allows a user to exert a force against the resistance force. A fluid displacement device is coupled to the exercise machine assembly and rotatably driven by the force exerted by the user. A fluid container has a hollow body enclosing the fluid displacement device, allowing for the fluid displacement device to rotate therein, and encloses a fluid. The fluid container includes an inner reservoir and an outer reservoir that cause the fluid-based resistance force to vary based on amounts of fluid in the inner and outer reservoirs, respectively. Further, the inner reservoir has one or more openings through which fluid can flow from either of the inner reservoir or the outer reservoir to the other.