I typically commute 36 miles RT to work by bicycle three days a week, and usually take a weekend ride for fun of about 40-50 miles. I assumed I was a pretty strong rider.

My wife recently started taking spin classes at the local gym and I decided to accompany her this weekend.
I was shocked at how difficult I found the class! The stand up and pedal position caused a killer burn in my thighs, and overall the cardio workout was quite robust. I am really surprised at how different these classes are than my riding style; I guess having all those gears and a properly adjusted bike frame have spoiled me.

Does anyone else out there have thoughts on spin classes?