Join Date: Jul 2007
Location: Northern Colorado
Spinning class will definitely work on your aerobic engine, and your basic pedal mechanics. But nothing is really like really riding. It takes more resistance than most of those spin bikes can handle long-term without starting to have mechanical issues for me to simulate "real" hills on a spin bike (usually stripped brass resistance-pad screws at my gym, and they have some of the more sturdy spin bikes).
When there is snow on the ground during the winter around here, spin class is my primary aerobic exercise. It does not "prepare" me for riding outside on hills, dodging traffic and potholes, etc., but it is also a lot less boring than sitting on a stationary bike trainer. It beats the hell out of that, for sure.
As for high temperatures? I ride anyway, and alter my route to be able to stop at a gas station or convenience store if I need more than 2 bottles of water during the ride. Well...sometimes I will skip if it is over 100 degrees and the air quality is so bad that they have a warning on television about it at the same time, but otherwise I ride.