Went to the gym today, weight training. Was almost done doing legs, then I felt exceedingly sick. I felt either that I was going to vomit or pass out. Went to front desk told them to call the ambulance. By the time they got there, I felt better and declined to go to hospital. When the they took blood pressure it turned out to be a bit low, and they got there like 15 mins after the call my heart rate was 110 bpm. I had two sandwiches an hour before working out. Could it be I overworked?