I have now attended my first spinning class!!
It was actually pretty good ... not overly difficult, but still a bit of a workout. The instructor had a good variety of activities (sitting, standing, faster, slower, etc.). He did say he started a bit easy because it is the first class, and that the emphasis of the class is to build speed. He is from a triathlon background so has some real cycling experience.
I discovered that the bikes have SPD pedals after all (on my first visit to the facility, it was hard to tell from a distance) so I'll be wearing my cycling shoes next time instead of runners.
And then after the 60 minute class, I headed over to the weights room where I ran on the treadmill for 20 minutes and lifted weights the rest of the time. There's also a pool in this facility so I may swim after my spinning classes sometimes. I actually wished I'd brought my bathing suit today so I could soak in the hot tub for a little while at the end of my 2 hour workout.
I plan to do this twice a week till the end of March. I think it will be a good supplement to my outdoor cycling!