So if you want to be able to eat more and still maintain your current body weight, get up earlier and exercise before breakfast. If you want to lose weight, get up earlier and exercise before breakfast. And if you want to be in a better mood all day, definitely exercise before breakfast. Researchers at the University of Vermont found that aerobic training of moderate intensity, with an average heart rate of around 112 beats a minute -- elevated, sure, but it's not like you're hammering away -- improved participants' mood for up to 12 hours after exercise.
In a way, moderate-intensity physical activity is that "magic pill" a lot of people are looking for, because the health benefits go beyond keeping your waistline trim: Not only can it reduce your risk of cancer, stroke, diabetes and heart attacks, but studies have shown that physical activity can significantly improve the moods of patients with major depressive disorders.