When all else fails - do Abs

I forgot my camera today, and I wanted to film my leg work this week so I had to opt for something else. My entire upper body had some residual soreness from last week so I had to think of something that would be "overtraining", so I figured I would do abs (which I honestly have never done in an isolation workout). There are some advantages to working out without a partner (all alone for that matter) and that is you don't have to be embarassed with someone watching you struggle like a lame school girl.

I remember the good old days lifeguarding at Deseret Gym, with my favorite US Marine, Mike Carroll. This guy was in top notch condition. I remember the Infrared Body Fat Percent machine pegged him at -3% body fat. How can you have negative body fat? Anyhow, I remember him teaching me tons of calisthenics that he used to do as a marine and how we used to be machines doing them together. One of the exercises was flutter kicks so I started out doing those:

Flutter kicks: 4 sets of 25 (4 count)
Legs up crunches: 4 sets of 25
Captain's Chair: 2 sets of 15 (crappy form and too fast), then slowed down and did 4 sets of 5
Bicycles: 7 sets of 15

Those bicycles were bad! I didn't get a burn from those, just a wedgie and I could barely get my shoulder blades off the ground. Touching knee to elbow was totally impossible as my flexibility and gut just wouldn't allow it. Today was completely humiliating, however it was kinda fun.

Abs are without question my weakest muscle group next to my legs, so I really want to set a goal to do them isolated like this at least once a week. I think from now on my routine will go like this:

Monday: Chest
Tuesday: Legs
Wednesday: Biceps/Triceps
Thursday: Abs
Friday: Shoulder/Back/Neck

This way I can rotate my muscle groups in a way that should prevent overtraining. I totally respect you guys out there who do abs on a normal basis and can do sit ups without breaking a sweat.