Just wondering about the AMRAP approach, is that something you heard about or was recommended to you? It sounds like a fun way to train actually.. set up a block of time and do as much work in there as possible. Would you usually do any sort of progression for this (incr weights, total reps, decrease rest etc)?
I first heard about it from Mike Tuscherer, an elite level powerlifter and coach who also set up Reactive Training Systems. From time to time I sign up to their online coaching and programming (well worth a look as his knowledge is superb, just be aware that the focus is purely powerlifitng)
GPP stands for 'General Physical Preparedness'. Being a powerlifter nearly all of my training is centered around the big three lifts, or variations of them. This means that some things like rows, can get neglected in day to day programming.
Izzy from Powerlifting To Win (a guy who really knows his stuff for all things powerlifting) explains the concept of it really well here;
I try and do 1-2 GPP days a week in order to address some of the muscles that otherwise would get neglected, and also increase fitness levels as this can improve recovery times and help to disapate fatigue. Also I find hi volume bicep work helps prevent bicep/forearm tendonitis when my deadlift volume and intenisity increases.
The way in which Mike recommends doing the AMRAP is to pick a weight that you can do comfortably do 8-15 reps with and basically just do as many reps as you can in that 7-10 minutes. Its a way to get a lot of volume in a short space of time, and also ensures that you are not using a load so heavy that will affect your recovery capabilities for the main lifts during the rest of the week. It also gives a bit of an aerobic capacity to it and is a nice way to break up the stress of constant heavy barbell work.
As for progression, I'm not to worried, and I dont really keep track of how many sets/reps I did in the 10 minutes, but I do try and increase the load from week to week if I can.
Hope that helps explain it a bit. I've attached a PDF that I got from Mike when I last ran one of his programs. It also has some other interesting things on it.