weight lifting traing after gastric

Hello I am jaswinder Gill, My opration gastric bypass was on Feb12,2007 I am well right now.I am working in GYM, eleptical croosstrainer for .40 to 1 hour,Treadmill for .30 hour then sauna for .30 hour. I have loosed from 385lb to 332lb now. Can I do weight traing for chest & arms for not to loose skin.Tell me any other exercise for bally fat. Thank you very much.