I am a 27y/o female who exercises 3 times a week. I am average height and weight and in otherwise good health with no known ailments. When I run (generally outdoors) and my heartrate reaches about 170bpm, I find that my chest often hurts (burns), I feel extremely fatigued and wheeze. I ve not seen a physician as of yet so I am wondering what the chances are that I am simply out of shape rather than have EIA. This doesn t seem like a lack of fitness from my perspective.