Is throwing up the solution for a flat stomach?

NO- that is never : The solution! to tighten ab's do crunches, reverse crunches, exercise ball crunches, pelvic thrusts, lying leg raises, side bridge ; “bicycling” exercise on your back. Engage in regular aerobic exercise (i.e., running, swimming, nordic track, bicycling, kickboxing, walking, cross country skiing, hiking, etc.). Eat healthfully - no starvation. Don't over-exercise. Don't lose health over looks.