The Most Efficient Abs Exercise for Flat Abdomen in 1 Month There isn’t anything more efficient than this. I’m telling you. I’ve been doing many exercises but this one is the “mother” of all. Being overweight or clinically obese is a condition that's caused by having a high calorie intake and low energy expenditure. In order to lose weight, you can either reduce your calorie intake, or else exercise regularly and reduce your calorie intake at the same time. It's always more...