Same for me.
I got this flexibility and back strength from doing decades of yoga.

It really helps with road cycling and having and keeping a more aero position.

The common phrase, often attributed to Joseph Pilates, is "You are only as young as your spine is flexible". A related variation often used in yoga contexts is, "You are as young and healthy as your spine is strong and supple". These quotes emphasize that spinal health directly correlates with vitality and overall, youthful physical function