Full Disclosure: I currently work for TrainerRoad, but I'm a developer, not in marketing, so what follows are just my personal opinions. I find training indoors to be a more efficient use of my time, but would much rather ride outside over the summer. But what usually happens is my fitness drops as I don't stay as focused when I'm riding outside. So this summer I'm going to try to keep a couple of sessions a week indoors. If you've never done a structured training program for cycling, something like TR can help, and we're getting into the Analysis side of things now as well, but I'll stop there. If anyone has specific questions about TR I would be happy to answer them via DM. As for Zwift, I signed up for the beta before I started working at TR but never tried it out. I've never personally seen the appeal, but if it gets someone exercising when they otherwise would not, great. I prefer to watch tv, movies, or read a book while on the trainer. You could do those while Zwifting I guess, and I know there are people who use Zwift and TR at the same time. So lots of options out there to make indoor training more tolerable for you. I'm a bit of a data junkie so I record all my fitness activities via a Garmin device (usually a Fenix 5x) which get upload to Garmin Connect and then sent to Strava, Cycling Analytics, Training Peaks, and SportTracks. I wish I had a power meter for my ice skates for when I play hockey, but have to settle for Heart Rate and SM02. It's pretty interesting to compare a game of hockey with a indoor ride I do and how well they match up (hockey shifts vs. vs short higher intensity intervals on the bike).