I find that I am most likely to fit working out into my day if I do it first thing in the morning. However, once I have gotten up (7:30), hydrated, eaten breakfast (usually 200-300 calories of protein and complex carbs, like plain nonfat yogurt, Fiber 1, & blueberries), and given breakfast 45(ish) minutes to settle, it's no longer "first thing" and, despite the fact that I'm a graduate student and I set my own schedule, some crisis has likely popped up with work or home that I need to deal with, and then I've lost my momentum.
I know people who work out before breakfast, but I've never tried this. I usually wake up hungry, but of course I know from experience that cardio usually suppresses hunger (until you're done anyway). Is this a good plan, though? Will you burn more/less/different calories if you exercise on a completely empty stomach? Is there a danger of feeling faint (if I'm not normally hypoglycemic)? Women's fitness magazines will tell you that you need food to "fuel" a workout, but I know all too well that I have plenty of stored fuel around my tummy and thighs!
Anyway, if people have had good or bad experiences with working out before breakfast.....
Thanks
Sarah