I'm sure you can relate to this: in the middle of the night I got up to go to the restroom and as I stood up my entire back locked up it felt like every muscle in my back flexed... pain is the word, I had to slowly sit and lay back down to relax the back. waited 5min and tried to get up again. I told this to my training partner and he couldn't comprehend why my back did that. I said your 24 I'm 44... you will one day.
Ha, ha!!
I'm about halfway between your ages at 35, and I can tell which direction I'm headed in.

I don't stretch and warm up like I should, although I've been doing much better lately.
One thing I've noticed that has really minimized general body ache is cardio. I've been doing at least 20 mins. at level 7 on the StairMaster, often with another 15-25 mins. on the treadmill after my workouts, and have noticed things "moving" a lot better than they did a few months ago. It hasn't negated any size or strength gains that I can tell, although I'm not exactly following a contest prep diet, either.

I've also begun using my foam roller and tennis ball a bit for myofascial work. Joe DeFranco has a couple of good videos posted on YouTube. In fact, I'm becoming a big fan of his articles and tutorials. I wish Poliquin would follow suit in offering more in the way of public videos.