There is one supplemental exercise I would advice whole heartily however and that is weight lifting. Although often rejected by martial artists who do not value raw strength as much as most other athletes do, weight training offers a wealth of benefits to the grappler. In my opinion weight training should be part of every grapplers training regiment. Grappling is very physically demanding pursuit. The constant falls, torque and strain put on the body are tremendous.
Weight training helps protect the body from the banging.
Additionally the weight room is a good place to get to know your body. Where your strong, where you weak. The gym is self quality time. Another added benefit is that it reduces the amount of recovery time needed. A body that has stronger muscle is also more responsive.