I decided to try to go head to head with Cathe on her barbell weight for leg work! Well I swear to GOD my legs are shakin like mad and boy is my core shakin too. I always knew we used and need our core but this is truly first time after a workout when my Ab's feel exhausted (besides straight ab/core work), I guess I'm glad to know I'm using them }( . I actually left out ab's, biceps and triceps section because I worked them hard yesterday and I thought I'll do 30 minutes of cardio today too.............well son left for school I stick in Kick max thinking I'll just to the warm-up and kick/punch combos :+ no way in heck, in the warm-up the little squats started to make my legs shake immediately wholey smolly I'm spent today! :7