Hi Heather

I'm sorry you felt so bad at your spinning class. Is it possible that you would have been pushing it a little bit? It's important to build in rest in your training schedule... A day or two a week, and a week a month too (with lower intensities, less volume, etc...).

Regarding your heart rate, I might be wrong, but I don't think you should be too scared. I am nearing 30 and I still hit 220 once in a while. I have a much higher heart rate than the charts would predict when I'm exercising. One value on its own is not a very good indicator, too. How did that 198 happen? What are usual heart rates/exertion rates combinations for you? Are you sure that 198 value comes from your heart, not from some interferences? What about your resting heart rate?

Take some light time/time off, and hang in there! You need to ride the distance for that MS150, but nobody says you have to sprint it!! Good luck!