I’m 43, and though I seem to get more injuries in the gym since I hit 40 (usually tendon overuse), I’ve noticed that proper nutrition and good sleep make a big difference in how my body feels. I also go to the gym at 5:30am and do an hour of free weight strength training 4 days per week.

If you guys are hurting all the time in your 40s, I would really advise you to do a full assessment of what you’re putting in your body and what kind of message you’re sending your body with your exercise routine. It might also be a good idea to get checked for markers of inflammation as well as testosterone levels. You should not have constant nagging pain at your age.

It's not literally pain all the time. More things like you said - much easier to overdo it in the gym or playing sports, especially if you don't warm up and cool down properly, plus occasional ridiculous injuries, like stretching too hard in the morning and having a muscle in your neck spasm as a result.