I had to delete and repost this thread for technical reason. Here's Rob's post.
Rob posted the following core workout:
It is always best to train the core in circuits.
Suggestions: Circuit1: The Flag x 5reps Dumbbell Side Bends x 6 Reps(per side)
Supermans x 15 reps
Medicine Ball Twist Throws x 8 Reps(per side)
Repeat the circuit 5 times and finish with a plank hold for time
Circuit2: Standing Wheel Rollouts x 5R V-Ups x 15R(if too easy add weight)
Russian Twists x 10R(per side)
Back Extensions x 12R Max-Set of Chinnies Repeat 5 times
Circuit 3: turkish get up x 5reps per side dead lift twist(AWESOME exercise) x 6R per side V-ups x 15R repeat 5 times and finish with plank hold for time.
There are numerous more combos to do, most important thing is that you target the whole core and go heavy instead of pumpin out 100 of reps on the sit up incline bench if time is limited and you are searching for a quick but challenging and functional workout do this: Turkish get ups x 5R per side(go as heavy as possible) dead lift twist x 6R per side(as heavy as possible) Full Contact Twist x 6R per side( as heavy as possible) and/or Standing water ball twists x 6reps per side(as heavy as possible) repeat circuit 3-5 times.