ERG mode is great for workouts because you can focus on putting out power and don’t have to worry about matching the workout power levels since the trainer does that for you.
The downside to this is that you never get out of the saddle, so a long ERG mode workout can really cause a sore butt. If you try to get out of the saddle in ERG, the cadence shoots really high and makes it almost impossible to pedal.
In my custom workouts, I work around this by inserting 30-second free rides, but that isn’t ideal because I mostly have to stand up and stop pedaling. Saves the ass, but drops my HR. I don’t know how people do the pre-programmed workouts without failing a segment or getting a sore butt. It’s not about how fit you are, nobody stays glued to the saddle for 60+ minutes unless they’re setting an hour track record.
What we really need are “out of the saddle moments” for ERG workouts, with high resistance, low cadence for 30-60s but no success/fail metric on the segment. Make sense?