Does anyone experience exercise intolerance? I'm a 33 year old female. I'm not overweight, but it's so hard for me to do anything. I like going for walks, but when it's time to come home I have to walk up a hill and I feel like im not even gonna make it up the hill. I get so out of breath, lightheaded and my heart pounds so hard. I literally feel like im dying. I've been checked out by my doctor. Bloodwork and have had ekgs for my heart which are all fine. I just feel like something is seriously wrong for something as walking uphill to be so strenuous. Could this be anxiety related? Or maybe I'm just in poor shape? I try to walk consistently but some days are just so hard.