ITS VERY IMPORTANT TO DO BACK EXTENSIONS AFTER A LIFTING...PUT 9-20 LB. BARS BEHIND UR NECK, AND UR ARMS OVER TOP OF IT. WHEN U PUSH UP OR STRAIGHTEN UR BACK...ALL UR POWER TO DO THIS IS COMING FROM UR BACK, AND UR ARMS R NOT HELPING U CHEAT. IF U LIFT, AND DONT LOOSEN UR BACK, IT WILL CRAMP, OR GET SORE.
100-