What hours do you work? When I worked nights it wrutal as 6pm-5am. It was brutal going home after work so I stayed and worked out. If you live close to work it isn't a big deal. What I did to stay awake is I just moved around. Since you are inside, get up and walk around. Do this a lot. What you eat is very important. When I started eating right, I didn't even need coffee. Things like salads with Olive Oil and vinegar are very light and refreshing and keep you up, unlike the greasy ass food. Drink lots of water.