I've enjoyed Billy's workouts over the years, always taking into account the poor balance of the number of moves on both left and right sides. However, he always delivers a sweaty, challenging workout - so I get over it. I did Core Express yesterday for the first time, and was amazed how I really felt the deep core muscles today had really been worked! Inner obliques too! I recommend this video to any one who wants a short cardio & core workout. I take away 1 star for the warm-up & cool down, which don't really provide adequate stretching, plus the lack of equal number of moves on each side as mentioned above. Thanks Billy!