Stick with the physio exercises for longer than you think you need to. Doesn't do any harm and all the more strength you can build up the better. This isn't just about training but everything else you use your knee for as well. When I dislocated and fractured my shoulder in July 2008 I had to wear a sling for a month and the day it came off I reached for something on a supermarket shelf and the muscles had wasted so much that my arm just drooped. However I booked in with a private physio a couple of days later to get things started and then saw an NHS physio for the next 2 months. I'd been doing the exercises twice a day and by the time I was discharged in October I had more or less full movement back. Quite a bad dislocation, as shown in the x-ray. I started the strengthening exercises in August and gradually phased them out by November. Had to take it carefully for a few months but I resumed Thai boxing in October, had a comeback interclub in February 2009 and my first fight in May. A couple of physios have told me that being in pretty good physical shape before the bike accident that caused the dislocation helped with the recovery. These days I've got full range of movement and I'm strong enough to pick up someone who weighs more than me.