How to fix raised shoulder posture? When riding, I have found myself in a posture where my shoulders are raised (like a shrug).  I assume this is a bad posture.  When I notice it, I correct myself.  However, sometime later I might find myself in this position again.

What can I do to correct this, besides just trying not to do it?

Is it a bike setup problem?  Can I do any exercises off the bike to improve this.
In my experience it may be a lack of core strength.  So you end up leaning on your arms more, to try and lighten the load on your mid-torso muscles and lower back.

Try moving around more at work, a standing desk might help.  Some stretches throughout your work day and before riding too.

If you don't wear cycling pants, consider getting some.  They offer support around the waist which I found helpful.