Get in the half-sit-up position with your feet anchored. Maintaining this half sit-up position while doing any movement with the arms will challenge the abs, and this one hits the delts as well.
Try to keep your spine and neck as neutral as possible. Go light and do the exercise for one continuous minute, or go a bit heavier and aim for 10-15 reps.
We all know what kind of training Chad puts his clients through, but what about Chad himself? Amazingly, his own training is mixture of Crossfit and H.I.T. Kidding! You'll be glad to hear that he practices what he preaches.