I don't get it. Cyclists are joining spinning classes in winter because ... it's winter. Fair enough. Then they note that it's not the same as cycling. If you just want the workout that's fine but if complain that it's not the same as cycling, then get back on your bike for some winter cycling. The workout is great. You tense up your body as you navigate and push through snow and ice like you don't summer cycling. And you work up a sweat.