The second field is for a second exercise of the same muscle group.  For example, you may choose to Bench Press as your primary chest exercise.  When you get to your secondary high-point, you switch to doing Chest Fly's or maybe a decline/incline Bench Press.  Just be sure to choose an exercise of the same muscle group.  One thing I have done is have a particular exercise be my primary one week and then the next week I would alternate and have that exercise be my secondary and vice versa.  This helped me keep from getting in too much of a routine and helps confuse the muscles a bit.  

Hope that helps and good luck!!

Mark

I've read all Bill Phillips books and watched his Youtube videos, and I remember something about the second exercise for the same muscle group targets the muscle from a slightly different angle, and works the muscle a little differently than the one before it. I just can't remember which of his books it was in or it actually might have been one of his Youtube videos I watched.

Hope that helps :-)

The high point exercises are great and add variety and angles to related muscle groups.  I do miss this in my current routine but will return to it on a challenge next year. trying a different type of muscle confusion right now and style.

Thanks everyone, appreciate the help.  I will add these into the routine.  

It is that slight variation (ie, going from bench press to flyes) where I really feel the burn.