Here's a plank workout for the "Hump Day"...kind of a half pyramid. And it has a surprise in the end :-). Actually the idea is to do the last plank hold as long as you can. If you manage to do the whole 3 minutes, congratulations. I can't, at least after a full gym workout (like to do planks in the very end).
This whole post can be copied as such to Kutya Timer for iPhone/iPad... it is turned automatically into a timed workout! Get Kutya Timer from the App Store: http://tinyurl.com/GetKutyaTimer
03:00 Plank for Your Life!
Link to Kutya Timer @ Apple App Store: