The Plank!

[FredClogs]

I used to do 2 or 3 minutes as par of my warm up routine and someone asked if I could do 5 minutes, so I did (I'm all man btw) but it's boring as feck and does make my lower back hurt. These things are like anything, there is a certain amount of physical strength and endurance needed but after that it's just mental practice, bloody mindedness and knowing that you can do it. I find it much harder raising my legs 6 inches of the floor for 3 minutes.

[TheJimi]

Doing planks are good for...getting better at doing planks

Ok, I'm only partly kidding, planks ARE good for ab activation but as Hoof says, there are many other, more functional and effective movements.