Um so I'm 17 weighing around 140 and standing a little over 5 feet 7 inches, an ex-cross country and track runner, I've been lifting weights for about 2 years now. I focus on bench press and curling a lot, as well as other things that strengthen arm and chest and back. I've been doing sit ups and pu...

I think push ups are best for warm ups. Since I've been working out, I've never really found push ups helping fitness level. If you want to work the chest area, presses are better.