My heel never hurt badly enough to make me stop running. I could still walk normally, and I could still run. Most mornings I’d feel some stiffness in my right heel for the first few steps, but once I got moving it usually felt manageable. Because it wasn’t very painful, I didn’t think much of it at first. I just figured it would eventually go away. I was paying more attention to whether I could run than to how my heel was actually responding to the training.