Four rounds for time of:
Run 400 meters
30 GHD Hip Extensions
Post time to comments.
Picture from CrossFit main page: http://www.crossfit.com/mt-archive2/hip-ext.html
Glute Ham Developer Hip Extension: Set up so that the pelvis is clear of the pads, and without any movement in the torso, extend and flex at the hip only.
A simple substitution is to lay a pillow over a chair or low object. The feet are then anchored underneath a bed, car, tied to the ground, etc.