you will `` feel the burn '' if you use the Shake Weight accord to direction . it will harden up you arm , chest , and choulder with continue -lrb- and proper -rrb- use , but do not be fool by the commercial . they show these huge bodybuilder dude use it and act as though they have just complete a pentathlon . believe it or not , not everyone will see through this exaggeration . the Shake Weight will , as I say , harden you up with continuous PROPER use , but it will not take you from couch potato to bodybuilder as the commercial seem to suggest . it be a decent workout on you schedule . overall , I be happy with the product , but not happy with the commercial ; it be market a little too well ...