Anymore, when I do a set of deads, once I am finished, about 15 seconds after I set the weight down, I have shortness of breath. I try to catch my breath, but it seems like I cannot get enough air in and I will start freak out thinking that I can't breath. This will go on for about 2 minutes, then I settle down. I don't push real hard with deads because of this. I don't do a whole lot of weight and my reps for deads are no more than 8. What could be causing this?