How do I keep from feeling like I'm about to regurgitate when doing heavy weight training?

Nausea. First, are you eating anything within 2 hours of your workout. If so then that is the first thing to correct. I workout fairly intense with a trainer and the 1 or 2 times i felt sick was when i ate an hour before our workout. Do you always work out heavy or do you change it up ? Muscles need to be confused and i highly recommend changing it up every week. Try doing 30 sec on and 30 off.