treadmill. So... the concerns about my helath got to me. I got off the airplane and went to the emergency department. 4.5 hours later (at 4:15 in the morning) I went home knowing that my chest x-ray is normal, and ekg is normal, and that my labs (cardiac enzymes) are normal. So... what is causing my chest pain and shortness of breath? I sletp for 4 hourse and then ran on the treadmill. I sued the treadmill to control speed and then I went relatively ahrd the lastfrom 4.25 to 5 miles. the last quarter was at 11 minute pace. total time 51:07. splits 10:02, 9:40, 9:49, 9:39, 9:16, 2:41 (5 miles in 48:26).