Being slim is no guarantee for having a flat stomach. Just walk around the beach on a hot summer day and observe the number of thin people with mild to extreme pot bellies. Being underweight does not mean a slim physique or good health. If you want to firm up your waist line, strengthen your back and trim that spare tire, read on.
The popular approach to flattening a stomach is often crunches, crunches, crunches. Then cardio, cardio, cardio. And finally count calories, calories, calories. Yep. It does the short run. But, I have it on teenagers to athletes, soldiers, …