Not that I’ve ever had a comeback, but I’ve noticed as I have gotten older, I’m naturally less limber than I was in my younger days, so a good upper body warm up each morning on a race weekend and some solid stretching seems to help keep me waaaaay stronger throughout the day and combats the soreness and stiffness each morning.
I had a short P90X phase, so I try to do some of the warm-up routines they have in those workouts, specifically ones targeting shoulders, neck, back and arms. Also, the Ab Ripper X routine is pretty great for core conditioning. And it’s only 15 minutes every other day so it’s easy to get done.
Your neck is probably fine from ripping around on gum ball tires/tracks back in the day, but it might be good to do some off-season neck training. I used to do a ton of neck work in my junior years.
Every year I notice that my first two races leave me pretty sore and exhausted but once I’ve built up that conditioning again I’m fine the rest of the season.