Hannah Demonstrates the Abmat Situp TECHNIQUE: This can be done holding several different leg positions, the most common is the bent knee. The mat should sit in the small of the back. ADVANTAGES: This core exercise forces core engagement. No energy should be coming from the legs. The abmat is in place for support. FAULTS: Common mistakes include using legs and hips to get the body off of the ground. To avoid this, you can have someone hold down your feet or tuck your feet underneath something. SCALING: This can be made more difficult by changing the positioning of the legs and feet. Such as a butterfly position.