Regular exercise results in many benefits for night-shift workers who need to stay on guard permanently. When you exercise, blood flow and oxygen delivery to the brain increase, making you more alert. By doing regular exercise, you can also improve sleep - and you know, a well-rested body functions much better during waking hours.
It may be hard to incorporate exercises into your routine, so look for sports or activities you enjoy and that help you release stress and, maybe, make new friends.
If you want to find out more about what happens to your body when you exercise regularly, check this video out (for specific content, check from 0:20 to 2:08):