Granted riding a Peloton stationary cycle is not cycling per se; it can be much more challenging. There is no coasting and no downhill on a stationary bike. That makes any stationary bike ride more strenuous than cycling outdoors. Sure indoors there’s no wind to contend with, though it can be modeled by increasing resistance on the stationary cycle.
Tomorrow I will attempt to ride for 8 hours or 100 virtual miles, whichever comes first. I’ve selected a series of scenic rides that total 9 hours of saddle time just in case my butt can handle 9 and not 8 and assuming I feel “good” as the day unfolds. The rides are recorded so there’ll be no cheating on distance or duration. Class start time is recorded as well. Any long break between segments will be apparent.
This ride will be entirely aerobic and in my FTP “endurance” zone. Heart rate shouldn’t break low zone three. This will be an easy ride made hard by time/distance. My training program calls for an endurance ride tomorrow. I’m guessing this qualifies.