My January 4-Day Split Rotation

I am hoping to kick it up a notch starting the second week of January with a 4-Day Split rotation. It uses all the workouts from Cathe's 4-Day Split DVDs, plus an added day of cardio and an added day of Pilates or yoga. Here's the current plan.

WEEK 1:
MONDAY.............Higher Intensity Step plus Chest & Back (Cathe Friedrich)
TUESDAY............Kickbox plus Legs & Core (Cathe)
WEDNESDAY......Advanced Step Challenge 2 (Amy Bento) or other cardio
THURSDAY.........Lower Intensity Step plus Shoulders, Calves, & Core (Cathe)
FRIDAY................Yoga Class or Bosu: Long & Lean (Chalene Johnson)
SATURDAY..........Boot Camp plus Biceps, Triceps (Cathe)
SUNDAY..............Rest

WEEK 2:
MONDAY.............Lower Intensity Step plus Shoulders, Calves, & Core (Cathe Friedrich)
TUESDAY............High Intensity Step Mix 2 (Tracey Staehle) or other cardio
WEDNESDAY......Kickbox plus Legs & Core (Cathe)
THURSDAY.........Boot Camp plus Biceps, Triceps (Cathe)
FRIDAY................Yoga Class or Fat Free Yoga (Ravi Singh & Ana Brett)
SATURDAY..........Higher Intensity Step plus Chest & Back (Cathe)
SUNDAY..............Rest

WEEK 3:
MONDAY............Higher Intensity Step plus Chest & Back (Cathe)
TUESDAY............Kickbox plus Legs & Core (Cathe)
WEDNESDAY......CIA-2601: Cardio Step Express (Gay Gasper) or other cardio
THURSDAY.........Lower Intensity Step plus Shoulders, Calves, & Core (Cathe)
FRIDAY................Yoga Class or Transformation Through Kundalini Yoga (April Bernardi)
SATURDAY..........Boot Camp plus Biceps, Triceps (Cathe)
SUNDAY..............Rest

WEEK 4:
MONDAY.............Kickbox plus Legs & Core (Cathe)
TUESDAY............Step Sweatfest (Tracey) or other cardio
WEDNESDAY......Lower Intensity Step plus Shoulders, Calves, & Core (Cathe)
THURSDAY.........Boot Camp plus Biceps, Triceps (Cathe)
FRIDAY................Yoga Class or Pure & Simple Stretch (Karen Voight)
SATURDAY..........Higher Intensity Step plus Chest & Back (Cathe )
SUNDAY..............Rest

The only thing that worries me is that my knees are still crackling like crazy. They crack even worse after a workout. Ugh. I'm not in pain with it, though, at least.