By chance are you a firefighter? Sounds like one of their typical schedules. I think it depends on the type of work that you are doing. If it is physical labor and such, then I definitely would prescibe a similar split that you have described. This will also affect your nutrition and your goals. If your goal is to lose fat and get ripped, then you MIGHT consider the reduced carb intake that your other response advocates. However, if your job is laborous, then this is definitely a bad idea as you will eventually overtrain between work and lifting. Also not good for gaining mass and strength. Another idea is to try abbreviated workouts (no longer than 30 min., 20 is better, not including warm-up)at a high intensity (%1RM) two of the four days that you work using compound exercises, taking a day off after the 4th workday, hit the gym using your normal routine two days in a row, take another day off, and repeat. With the three day split that I think you are describing, this will work well if you rotate body parts. That way one week you will hit the part with a short workout focusing on neural faciliation and the next week the part will get a greater focus on hypertrophy and metabolism training. If you find that you REALLY can’t get the motivation to get to the gym on working days, then try the split you talked about (4 on, 4 off). But if your job is demanding, even mentally, then eventually you will overtrain. If you your schedule is going to change soon, then try it. Otherwise give my way a shot. If you do try it, do the first two workouts during the first two days as this is when you should have the most energy and normal sleeping hours. Your recovery won’t be that great the other two working days, so that is what is so great about the off day after your work week. Lastly, try taking a little longer during the warm-up any days that you feel excessively tired, esp. after work. I find that I still get in great workouts if I just give my body a little more time to respond to the call of duty.