Yeah weights will improve, but it's not good to do to much. And you should learn how to lift them properly. But if you are unable to, try doing some more difficult push-up varations. Example: One Arm, Clap Push-Ups, Elevate Your Feet And Do Push-Ups, Arms Wide Push-Ups, Diamond Push-Ups, Hindu Push-Ups, I Mean Theirs A Shit Load Of Varations Avalible!