You need energy in order to exercise, so eat your meal about 1.5 - 2 hours BEFORE the workout. This will give you some time to digest the food and you'll get a much better workout out of it!
You should eat something after your workout too, to feed your poor starving muscles. Try something with some protein (eggs, lean meat, fish, chicken, cottage cheese) and some fibre-containing carbs (brown bread, brown rice, porridge etc.)
