when i do to like 4 russian twists or very little crunches and situps i get very bad pains in my back and cant really work my abs. i keep my back straight at all time, and try and focus all the weight to the ab region.
am i doing something wrong, or is that because i am thin, that my back is weak, please advise.
am i doing something wrong, or is that because i am thin, that my back is weak, please advise.