I am so sick of this. I wanted to sweat a little and decided to do cardio on empty stomach at a comfortable rate so it actually felt like I was doing something. I checked my rate every 3 minutes and it was 210-230 BPM for 32 minutes. I guit becasue I got scaird. I am typing this 20 minutes after and wondering what is going on. I feel great. I never pant, always a steady inale, exhale just like when I used to do cardio at 130BPM. I am going to give up and go back to HIIT twice a week in the evening. The past 3 weeks I have lost scale weight but did not feel like I was lsoing fat doing cardio at 135 BPM. I guees I have been at this far too long and need to quit for a while. I am now 175 pounds at 6 foot and sick of this.