Physically exhausting yourself doesn't actually take too much time -- do intervals at max exertion. If you take 'max' literally, you'll be exhausted after 10 minutes.
I got one of those bike-like thing to put under my desk. Initially for work but that wasn't working so now it's at home. I haven't been great about using it often but it is easy to use while playing games like I would anyways.
It might not be terribly efficient or anything but it's something.
You don't have to dedicate 1 hours of your day to this. Take the stair, walk/bike around, do some light gardening, ect. All small everyday stuff that exercise your body - and it works.
can you take a half hour to do a workout in your lunch break?