IMO, this isn't related to warmups. And it's worthy of its own thread, too.Biggest thing I notice as consequence of getting older is more small injuries when I'm NOT training. I can go pretty hard while exercising, but might pull a muscle in my hip while combing my hair.
I do know exactly what you mean as it happened to me in the past, but fortunately, not in the last 10 or 15 years or so that I can remember. I remember, maybe a couple of years after my initial recovery from my back injury, being able to already do a reasonably heavy deadlift but putting my back out once when I sneezed.
For me, time around meets provides an interesting barometer of this aspect of my fitness because I don't train much in the week leading up a competition and train even less in the week after (which is where I am in my schedule right now). I definitely feel some things I don't feel during normal training but, knock on wood, no injuries .
-S-