Ok, maybe I'll have them check it out. I've been having a bit more anxiety the last few weeks due to work, but seems unrelated to the heat rate after biking. I'm probably somewhere around 120 BPM for several hours after biking. Now that I think about it, it usually happens during after my weekend rides too, which are only about 12 miles. I just don't notice it as much because we ride in the morning, so my body has plenty of time to stabilize in the afternoon and evening.