I'm eagerly looking forward to my return to martial arts training, which (depending on my doctor's say) will be in a matter of weeks or perhaps a couple of months. But I didn't want to turn into a sofa vegetable in the meantime, so I had to figure out a way to work out while I couldn't attend class.
ACL surgery itself is extremely painful, your mobility is extremely limited, and I found it difficult to do much of anything at first. I did have lots of physical therapy to do at home as well as in the therapist's office, so this was my first step.
After reading this web page from GrappleArts I started doing push-ups and crunches--I couldn't do sit-ups yet because locking my feet under a couch would put pressure on my knee. I was able to maintain my ability to do 50 push-ups in one set, although I had to come up with variations on push-ups to avoid total loathing of them. For instance, at physical therapy, I now do 50 or 55 pushups with my legs supported on one of those big balancing balls. At home, I'll do 25 pushups with a 4-pound medicine ball under one hand, switch and do 25 pushups with the ball under the other hand. Sometimes I'll finish with 10 diamond push-ups--where you put your hands under your chest and form a diamond with your index fingers and thumbs.
I've started doing sit-ups also (knees bent, feet locked down) with my therapist's permission. But I think the crunches have helped a lot with my core--I'm doing 50 straight forward, and 50 angling to each side.
I also use the physical therapist's equipment for as much of a cardio workout as I can. For instance, I'm now using something like a StairMaster, but instead of only using it for 10 minutes, I double the time to 20.
And at my sensei's suggestion, I'm doing slow kicks--four different kinds of kicks, but extending the kick over a slow five count, holding for five, and then retracting for five. About a month and a half ago, I was finally able to balance my weight on my left leg again--I always follow my doctor's and PT's instructions--so I can now do slow kicks with both legs.
What can't I do? Anything that involves torquing my left leg with weight on it, like a roundhouse kick. Any fast, snapping kicks with that leg. I can't kneel on my left knee yet--something that worries me when it will come to grappling some months from now. I can't run well yet--I start limping within five minutes, even on a treadmill.
But I finally recently got permission from my physical therapist to return to a regular gym. The elliptical machine is fine on my knee, I'm going to try the rowing machine. And I'm going to begin hitting the heavy bags at the gym--I've been doing that carefully at home, now I'm going to try it with more vigor.