Bike vs Circuit training
If I understand you, you’re asking the alternate means by which people achieve the fitness benefit of cycling, rather than asking how people feel about alternatives. When I am riding (my preferred exercise) I tend to burn 10-13 cals per minute and stay in zone 3 for most of it, depending on the length of the ride. I do not like circuit training but since I know I can push myself to those zones and with that range of heart rate and calorie burn per minute, that’s how hard I work. And since I don’t like it, I only fo it for one hr at a session, I never push harder and I achieve very little progress - it just lets me eat desserts.