Baby steps build big successes. Forget about where you were before you needed to interrupt or change the path of your journey and evaluate where you are right now. Your muscles have memories and will come back as long as you just simply get moving. Taking that first 10 minute work out with Coach Nichol or walking to the end of the street. The point is to just do and do it consistently. Gently move back into the marathon you! It won't take long and if you do it right, you'll stay healthy.
Make sure you have cleared returning to your workouts with your doctor or physical therapist. The muscles will burn again, but it's much better than being hurt and laid up again.