I dont really know what my body type is but i used to be a distance runner and very skinny, especially arms. i ahve been lifting for a long time but in the last year really trying to eat as much as i can and have a good workout regimin(sp?) I'm 18 1/2 160lbs 5'8'' I have the hardest time trying to make gains in the arms, seens chest grows out of proportianlly bigger. I have been stuck at the same weight/size for a long time any advice? havn't done any AS yet