So I am 47, almost 48. Do not take offense to this - but a great powerlifter once told me that if I cannot squat on Monday and pull on Thurs. or Friday, then I am out of shape.
I took offense to that as I put quite a bit into this lifting thing. But deep down, I kinda agreed.
I will say this - my primary focus has definitely shifted to hard conditioning and away from lifting. I still do 5-3-1 of course, but when I wake up, my first thought is - what's the weather like and then is this a prowler, hills, or sled day. THEN, I address the lifting.
I do not get near as sore from lifting anymore - it's hard to get sore from squatting when your prowling hard and often.
And, FYI, I have not lost one bit from my lifting - in fact, I have gotten stronger.