Crunches & many more
You have a great deal of choices when it comes to toning your stomach muscles.
There are 3 basic starting positions to consider. From the back flat (supine) position you can do crunches and add a slight twist or touch elbows to knees to vary the theme. Planks (see image- torso/back straight with gut tensed) are a great means of toning your core muscles from the supine, prone, or sideways facing.