Only working the muscle you want to build is like using a machine to train with. It limits your stability and all around strength.  Muscle building programs are mostly created by weight lifters who have discovered  their way  to building big muscles.nnWhy don t these muscle building programs work for everyone nnThese are  major reasons why some muscle building programs aren t working Only working the muscle you want to build is like using a machine to train with. It limits your stability and all around strength. http://www.musclegainhelp.com/shred-hdx/