|No additional ab work needed. Pinako be mir'in.|
I see a lot of conflicting information thrown around the internet concerning ab work. The main two schools of thought are:
1. Indirect Training is all I need!
You do not need direct abdominal training. Squats and deadlifts will provide all of the training your abs need.
2. Sit-up or die faggatron
You need to train your abs directly. Without direct abdominal work, all of your training (see: large movements like squats and deadlifts) will fall to shit. Fire will line the skies. Blood will run through the street soaking the survivors of the inevitable nuclear Holocaust with iron and soot. They will be dragged. Down. Down. Down. Far below where there is precious air, they will meet death alone should they ignore their planks and situps on large bouncy balls etc etc.
So who is right? Well, both really. The idea of training your abdominal muscles is rooted in training your body to brace itself. Although not apparent with lighter weights (which allow you to get away with damn near anything), heavier poundages demand that you get tight or fail. At the risk of borrowing (see: stealing) deadlifting champion Andy Bolton's words...
Imagine you have a box. Reinforce the box on all but one side, then have King Hippo jump on the box from a 5 story window. Your box will explode out the one end that is not reinforced. Also, King Hippo is dead.
Now take the same box, but reinforce it on all sides. Have King Hippo jump on the box from a 5 story window. Your box, safely reinforced, will buckle but not break. Also, King Hippo is dead.
Moral of the story: a strong set of abs will protect you from injury and allow you to lift more weight.
But I digress. How you earn your ab strength is up to you. You can brace your abs on every compound movement (to train them indirectly, which you damn well should be doing) and/or work them directly with weighted situps/raises/planks/etc. Let's be honest here. Direct ab work is not sexy or fun, but it may pay dividends to your training goals to bite the bullet and make it a habit.
Everyone needs to train their abs indirectly. Consider direct ab work as another feather in your cap. Get stronger.