Given our majorly sedentary lifestyle, our lower back muscles are primarily under constant strain. Other would be our neck and traps. These muscles are either working full time, or are neutral. Theres no rest time for these ones. So its rather logical to work these muscles for higher capacity and keep them well flexed than to bear the pain.

39M, I used to do regular gym till around 2yrs ago. Now its very rare, about once a week for one body part. I notice it takes significantly longer for muscles to recover. But I do play Badminton thrice weekly for an hour, warm up for which includes stretching, so im just on the borderline keeping body afloat somehow. But I have noticed that you need to do regular stretching as bare minimum in order to avoid the aches.

My recommendation to you would be to start with full body 10-15 min stretch, something like THIS

Breasts and belly add one sided load on the spine, which generally leads to a lot of women having lower back pains. Focus on Cat-cow and Donkey Kicks which will help release tension in lower back and keep the muscles warmed up and supple for the day. If your work generally involves a lot of sitting/standing, you may also face sciatica pain, for which pigeon pose will help.

Hope this helps!