Or you keep saying to yourself... "If I only had that fitness machine I would be motivated to work out". It is also important to note, that for many people, a flat stomach is not in their genetics, even if they are in good physical shape. Some stomachs have a small curve, and all the crunches in the world won't change that. However, the exercises and equipment discussed below will help tone, strengthen and define your abdominal muscles. Home Gyms In conclusion... Crunches can also be done on an exercise ball and many feel it is more effective than standard crunches. You sit on the ball until you are lying with your back fully extended on the ball. Tighten your abdominal muscles and then lift your torso up off the mat toward your knees. Return to the extended position and repeat. Maybe you already have a collection of different exercise devices... but you are convinced that with this new contraption you will definitely reach your fitness goals. Thinking about exercise, talking about exercise, researching exercise