An exercise machine having a rolling platform and adjustable bar members. The platform is supported on frame rails, and is biased by springs towards an end of the machine. The rails have a rectangular cross-section angled 45° to horizontal, and roller assemblies on the platform include wheels angled to engage the surfaces of the rails substantially normal thereto. The adjustable bar assemblies include upwardly extending bars having upper members that are rotatable about a generally vertical axis so that handle portions at the upper ends thereof extend in different direction. At least one of the bar assemblies is also selectively pivotable about a horizontal axis to positions in which it is engaged by a locking assembly on the frame of the machine. The machine enables the user to perform a wide variety of exercises in reclined, prone, seated and standing positions, both on and off the platform.