DAY 1 in the books

Okay, Day 1 of P90X is in the books.  I am doing the Lean Program.  I must say that I am a wussy.  The exercise they were doing (all core work) were, for the most part, exercises that I have done either during athletics or in the military.  However, I don't recall them being so hard.  Must be due to the Monster Truck sized spare tire around my middle.