I have a hour workout using various weights which includes all the usual upper body muscle building stuffs and I've also downloaded an app for my iPhone called 'Couch to 10k' and do both of those around 3 times a week. The app's really great.
My only barrier is not always having time and sometimes I haven't eaten enough throughout the day to actually fuel myself to do everything.
But once it's all done in one day, apart from being knackered, it feels good. Like I've really achieved something.
Obviously I also go airsofting, and with my 5kg M16 and equally heavy set of magazines, gas, ammo and pistol, I probably get a lot more excersise than most other people there, because it feels like I'm giving a child a piggy back all day lol.