As a retired professional endurance sport athlete I can say without a doubt... Just do as much as you can without making affecting your current injury. Too many people just sit it out fully and wait. You have to go do something. Anything. Then, when getting strong again, slowly get back into normal routine.

If you can't run; then go walk. Or walk on treadmill at incline. If you can't do that; ride a bike, or swim. Maybe upper body only stuff.

Now that I just stay fit because I love it and it's not my job, if ever I'm silghtly injured I go do something else for a bit. There's millions of things to do in the world. My favourites: mountain biking, dirt biking, road cycling, wind surfing, running, hiking, swimming, weights.