Working out first thing, and pre-workout nutrition

I workout first thing in the morning when I get up - it is the only time of day when I have the time and motivation to do it. I have tried having a snack or a pre-workout drink before working out, but it generally makes me feel heavy and nauseous - I prefer to get up, drink some water, and get straight into it. Then I eat afterwards. I am wondering if anyone else does this, and if you feel it impacts on your workouts at all. I find if anything I workout better on an empty stomach, and I don't feel I am lacking energy at all. Thoughts?