Originally Posted by
OBoile
Wow. That can't be right. Edit: unless you were doing alp d'zwift or something.
I checked my most recent Zwift ride along with a solo ride (using TT bars), a hilly ride with just one other person (he did most of the pulling) and a group ride. The kj per km were:
Zwift: 21.45
Solo Ride: 23.66
Duo Ride (hilly): 23.86
Group Ride: 22.14
Zwift was the lowest for me in terms of energy expended per km travelled. I checked the last Zwift "race" I did, one of the ones on the World Championship course, so quite hilly, and it was 26.11 kj per km. So, slightly higher (due to the hills and me riding at a much more intense pace), but still very much in the same ballpark. I don't see how you could get triple the energy spent per unit of distance like you say.
I did my comparison using the BKool app/program to control my trainer using a route I had ridden in real life as BKool will import your ride data from Strava if you have a premium account with Strava and a premium account with BKool.
The graphics and social structure of BKool aren't as nice as Zwift, but being able to import .GPX data into the app to train for a route is really nice.
I labeled Zwift in my earlier response as most people understand what Zwift is, but many here in the US are unfamiliar with BKool. BKool is a Spanish company.
My first smart trainer was a BKool Pro (1st generation).