providing an exercise device comprising a platform, two rigid arms, and a curved base at a lower surface of the platform, the two rigid arms extending generally parallel to and away from the platform, the arms being located at generally opposing edges of the platform, each arm having a handle and at least one notch, the curved base being selectively attachable and detachable with respect to the platform;

providing at least one resistance band having a lower end secured to the exercise device;

inserting the at least one resistance band into the at least one notch;

extending or retracting at least one of the arms in a direction substantially parallel to the platform;

contacting the device against a support surface, by contacting a curved surface of the base with the support surface;

the user stepping on the platform with at least one foot, such that at least a portion of the user's body weight is supported by the exercise device;

the user grasping the at least one resistance band by hand;

the user pulling the at least one resistance band through an angle;

detaching the curved base from the platform;

attaching a roller unit to the lower surface of the platform, the roller unit having a roller configured to rotate with respect to the platform;

inserting the at least one resistance band into the at least one notch;

placing the roller in rolling contact with the support surface;

the user stepping on the platform with at least one foot, such that at least a portion of the user's body weight is supported by the exercise device;

with the at least one resistance band inserted into the at least one notch, the user grasping the resistance band by hand; and

the user rolling the roller against the support surface while keeping the user's upper body generally upright with respect to the support surface.