I have a lot going on right now (hopefully, it will all be over at the end of September - the stress along with it) and I'm working all the overtime I can get. This usually means 4 hours at the end of my shift. Thus, I'm working from 2pm until either 10:30pm, 12:30am, or 2:30am... usually 2:30am.
Before I started working all those hours I was alternating cardio and weight training days, often doing one morning session at home and one evening session at the gym. I was already becoming a little burned out by that and started dropping the morning cardio so I could get some rest. But now that I'm working all those hours the one thing that has remained constant is my post-work weight training session at the gym, three times per week. And the cleaned up diet, of course.
When I'm coming down to the end of a 12-hour shift, after having been on my feet all day, doing lots of lifting, pushing, and pulling and dealing with my aching feet and back, I think 'I can't... I just can't...' But then I pull out of the parking lot and pull up to the STOP sign. Right means I'm going home but left means I'm going to the gym. I'll think to myself 'It's a half hour... I can do this,' then I let out an exhausted sigh and turn left.
My workouts these days come from Chad Waterbury's Huge in a Hurry book (can't recommend this book enough!). The foundation of all his full-body routines centers around three compound moves: one push, one pull, one squat variation; each done for 24 reps, broken down however you like (i.e. 4 sets x 6 reps, 2 sets x 12 reps... whatever), preferably performed in a circuit. These moves get all my muscles firing, my results have been unreal, thus far, and my joints don't ache from a bunch single-joint moves. But the thing is, even at 2:30am, a workout that short is ridiculously DOABLE. And working out at 2:30am... I swear, the second I get to the free weights area of my gym, usually completely devoid of people at that hour, I magically pop awake. I walk in like freakin' Julie Andrews in The Sound of Music, feeling like twirling around with joy at having it ALL to myself. I can plan out what I'm going to do, often doing two circuits of 6 different moves.
Yea, 2:30am works. In fact, on nights when I get there at 12:30am the place has way too many people!
As for late night/early morning runs. I can see most of these ladies do their runs on indoor tracks at the gym but, really, I'm surprised there aren't clubs for outdoor runs at weird hours. Get a group of 20 people running outside at 3am... that could be really fun. Heck, I'd be up for that. Wonder how much interest exists for such a thing...?