Yes two classes is def good.I tend to get there. Adjust the bike and fit my keo pedals a bit rapid. Then climb for twenty mins, then first class, then pedal in between class, then do the next class then bike home.Only one problem . Two hrs looking at lots of women in lycra.Spin is such hard work. 70 mins on rollers earlier with 20 1 min sprints chucked in. Then a run up lantern pike.