Question: When I ride outdoors, I concentrate on keeping a quiet and relaxed upper body. I thought I was successful until I started riding on my indoor trainer where I can see my shadow on the wall. I noticed that my upper body moves about an inch or so from side-to-side as I pedal. Is this a form problem, or an artifact of having the bike locked in the trainer? — Jim B.
RBR Replies: I suspect that your body is moving while you ride indoors because your bike can’t.
If you could watch a video of yourself while riding on the road, you’d probably see at least as much back-and-forth bike motion even if your shoulders and upper body were relatively motionless. But when you lock the bike into a trainer, your body does the swaying instead.
The shadow you see on the wall is a great biofeedback mechanism to help you achieve a quiet upper body. Even better is a large mirror, which lets you assess your pedal stroke, too. And, of course, you could always record a video of yourself with your phone or tablet.
I don’t think that the small movement you describe is a problem. Most riders can only wish they had an upper body as relaxed and still as yours! And remember that some great riders, such as Eddy Merckx, had an almost shocking amount of upper-body movement, especially when climbing. It sure didn’t slow Merckx down!
You don’t want to intentionally accentuate movement, but it’s fine to let it occur naturally. It helps you establish a pedaling rhythm. Fighting it could waste more energy (and concentration) than it saves.
When riding outside, you can watch your shadow if the light is right and see how smooth (or ragged) you are. Best time is around solar noon when you’re riding north (sun is right behind you). You get a good sense of how much your body is (or is not) moving.