Hi guys!

I recently had a bike fit with a Retul guy local to me, and during the fit he said the flexibility in my legs and lower torso was pretty good, so I can ride an aggressive position - but his advice was to work the flexibility of my neck, shoulders and upper back to be able to ride that position comfortably as I lack some flex there now.

Does anyone of you guys have tips to increase flex there? What exercises should I do and what stuff would I need for that? Foam roller and/or resistance band?

Thanks in advance!