For time:

30-25-20-15-10-5 reps of the following

- GHD sit-ups

- Back extensions

*Scale abmat sit-ups if unable to preform GHD sit-ups, prone row for back extensions, 3 x single unders for double unders.

Demo video for GHD's: http://www.youtube.com/watch?v=t9kra8Mg_bE