For me, keeping it simple - I just maintain a routine. My lunch time is for exercise and I don't compromise on that. I figure out where 1 mile is and do my best. When I was 25, it was 7 minutes at 40 I'm happy to crack 10 and then there's another mile back. That's 2/3 of a 5K. If I'm tired, sick, hungover - then I still go. I'm not reachable at lunch and my coworkers get that. I try to do some weights too, but it's the routine that matters, imho.