Trying to learn more about regular stiffness and joint popping
42 yo male, 6'5, lean build. I don't follow a workout routine (I know this is my first issue) but my job keeps me fairly active so I'm not struggling to do everyday activities. With that being said, my muscles feel tight and sore all the time and it feels like every 15-30 minutes my joints get stiff and crack often when stretching.
I have always been good about drinking water so I don't think it's a hydration issue. In the last 4 months I've been stretching daily and also throughout the day. I try not to sit as much and just keep my body moving, but I'm not seeing much of a change in this respect. And while my muscles often feel sore, they are never in pain. My mother suffers from Rheumatoid Arthritis, so I thought maybe I was starting to show signs, but she always complained about her joints hurting, and mine don't hurt. Just more of a "you haven't moved in 15 minutes so everything is stiff."
I guess I'm just trying to find out if I am in fact just getting old and not working out and stretching enough, or if there is something else I should be looking out for or thinking about. My PCP seems to think it's just age and the lack of training. Thanks for any insight.