It’s been my experience the last three months of riding SS only that I have at least been able to tone and strengthen my core and upper body with relatively few other workouts (too nice out not to bike!). I doubt that I’ve added a lot of muscle mass but that isn’t my intent.

When I’ve used the elliptical or done my circuit training, I’m able to work with more intensity and for longer, so that hasn’t suffered for the heavy rotation on biking. But I’ve changed a lot of things up to make that happen and riding more like BMX than road.

Edit: it occurs to me that beyond the much higher fraction of standing work, there is probably a lot more core and upper body work needed because I raised the bars to be about an inch above saddle height. Since my trunk weight isn’t helping as much, I have to maintain more tension on the bars through the arms and core to keep from sliding back off the saddle.

Otto