It helps if you can eat anytime on the job, that way you can still get in all your meals and then dedicate the whole lunch hour to get in whatever type of workout you can. Granted it's not the best amount of time to get in a lift, but its something. What helps at my job is that now they've also started spin classes at given times during the week. This kind of helps because then there aren't as many people using the gym and you can get to whatever equipment you like.