Fitness expert Stew Smith demonstrates situps.

Sit ups with hands interlocked behind the head. These are used by the US Army, FBI, and DEA. Many other law-enforcement agencies also use this method of sit ups for testing in contrast to the hands crossed over the chest used by the Navy, Air Force, USMC and many other law-enforcement agencies.

To master Situps / Curlups for the new Situp PUSH workout read: The Proper Technique for Curl Ups.