80 RPM

Today was supposed to be a spinning class. But I didn't go. I opted to sleep for almost 2 more hours instead. I figured I could ride the stationary bike instead. And I did. At first, I was able to go about 22-23 mph with a cadence of between 80 and 90. But that lasted about 10 minutes. I got tired. I rode the next 10 minutes at 18-20 mph with a cadence of between 70 and 80. I had planned on a 30 minute ride. It didn't happen.