I'm 5'11", 180 lbs. Pretty cut and Ive never really lifted weights in my life, but I'm a big fan of working with my own body weight like pushups and pullups. and such. I can do 15 chinups or 15 pullups in a row no problem. But I went to my friends gym and tried to bench 145 (his warmup) and I couldn't do one. WTF? Is doing chinups, pushups, etc worthless?