Started doing yoga once a week last December. I used to do it back in my 20's, so it's been a minute. I surf 5+ days a week, usually between 1-3 hours a session. Lift weights and run some when it's flat or I'm feeling motivated. But, my job keeps me in a chair and I always had a sore neck and back. Now I don't. Yoga's the only thing I'm doing differently.
My Father In Law's been surfing for 50 odd years. Had to have 3 vertebrae in his neck fused last year. He has lower back pain as well. I got him a paddle air vest last October and he's been using that. Says it helps a lot.