I would definitely feed Harvey twice a day..Boxers are prone to bloat so the 2 times a day feedings lessens that...Excessive sleeping is a side effect of being overweight, also depending on how long it's been since his leg was hurt, he may just not feel like doing anything. I assume that the vet says he has fuly healed? If so, start taking him on walks, short at first, see how he does, maybe 15-20 minutes and work up from there..Was the leg broken? You can also give him a baby aspirin each day to help with inflamation and pain as well