What is the best thing to eat before an early morning workout when you don't have time to wait an hour or more before exercising? I've been drinking a Slimfast. Is this a good idea?

I am not a big proponent of liquid meals. There's nothing wrong with occasionally using these meals in a pinch. But if this is your daily breakfast, I hope you'll rethink your schedule and plan a simple breakfast made from wholesome food. For instance, you could prepare a smoothie of fresh fruit and yogurt the night before. Or have orange juice before exercise and a whole-wheat bagel and cheese right afterwards.