Whether you are a member of a gym or not, there are plenty ways of getting in an exercise workout. It doesn't have to be a 1 hr session, it can be a simple 15-20 min session. Also, you do not need any equipment to get an effective/efficient workout in either. Of course, having dumbbells or kettlebells, and weight plates or even full-on machines may make it more fun, however, those are not required to burn many calories in a short period of time.
If you happen to work an extended length of time at work (you consider yourself a workaholic... 12+ hours) you probably won;t have time nor the energy to go to the gym after or before work. So instead, why not have some fun at work and mix in some simple exercises that target all muscle groups. You could even engage your co-workers to join you if possible. Here are some very simple exercises that don't require much space, equipment, or time to perform.
2. Wall sits
4. Jumping jacks
5. Walking lunges
6. Dips using a chair
You could begin by doing each exercise for 30-60 seconds and completing 3-5 sets of each. Rest 1-2 minutes between each set. This simple routine would take about 12-25 minutes to complete, making for a perfect pre-lunch workout.
If you work outdoors as opposed to an office job, there are options for you as well. I once heard of a Landscaping owner incorporating these exercises into his (and his employees) daily work schedule.
1. 20 Pushups before every lawn they mowed
2. Gas-can curls
3. Truck bed/trailer dips
As you can see, exercises don't have to be conventional, just have to be creative. I hope this gives you some extra motivation to sneak in a workout next time you don't have time, or feel like going to the gym.