A little tip. If by chance, you're not able to always get to the gym to work out, a couple of things that can be beneficial to you that we all do, even the guys that fight.
You can go for a jog. Jog as far as you feel that your body can take you.
Don't try to do more than that, because you'll just come back and just be crippled for the next two weeks. Deal with the distance you can handle first. It could be a mile, two miles. When you come back to the gym or you come back to your apartment, if you have a rope, jump rope for 10 minutes. Jump rope is a great way to keep yourself in shape. When you're jumping rope, try not to school girl jump rope. If you can, start off with your feet together as you turn the rope. Then you want to pick one leg up, one leg down. Again, important part, keeping the balls of your feet off the ground as you jump. You can jump for 10, 15, maybe 20 minutes.
No more than 20 minutes. After that, you can run through some abs for 10, 15 minutes, or some push-ups. Within itself, that is an aggressive, good workout if you're not able to get to the gym every day.