From a side plank position, lift the top leg up and hold for the prescribed duration. The star side plank can also be done with the lower arm straight and hand on the floor.
 
Purpose
The star side plank strengthens the obliques and QL for lateral trunk stability, and adds strength work to the lateral hip for improved hip stability.
 
Programming
3-4 sets of max holds (not to actual failure) at the end of training sessions is a good prescription. Shorter, less demanding durations can be used in a warm-up for preparation as well.
 
Variations
The star side plank can be done on the elbow or a straight arm, and the leg can be help up in place or lifted for repeated reps, or it can be performed as a side plank lift plus leg lift for repetitions.