of course what scrap said, plus plyometrics. but always be careful doing them as injury can result if dome incorrectly.

for example, a slow bench press of 300pounds is great, but if it takes you 10seconds to lift it while turning beat red in the face it's useless to boxing. However, clap push-ups, although using far less weight, are far better for fast twitch muscles delevopment and thus good for explosive movements as in boxing.