"The L-sit is performed by supporting the body entirely by the arms and holding the legs straight out in front. The body forms an “L” thus the name L-sit. The exercise (we can hardly call it a movement) is isometric, i.e., it involves no joint movement. Being isometric, we quantify its performance not in reps but by time. "We not only contend that the L-sit is functional but that it is the most functional of all abdominal exercises.” —Greg Glassman, CrossFit Journal Issue 09 - May 2003 | CrossFi