I think I mentioned I’m taller now. I was 5’9" from junior high until a couple of years ago, when the measuring thingie at the doctor’s office said I was 5’10". Both were with normal-heeled shoes on.
Before, I couldn’t see the top of the refrigerator without going up on tiptoe, even with shoes. Now, when I make an effort to stand up straight, I can see the top of the refrigerator barefoot. Mrs. Andy has been deficient cleaning there. (inside is her job, outside is mine)
I think the main thing is spinal curvature. I have spinal kyphosis, where my head sits forward of my shoulders. That used to be a "senior citizen" thing, which I am, but it’s common all the way down to teens now, blamed on gaming and cellphone use. I’ve been doing exercises to mitigate that. Not as much as I should, because they’re tedious and painful, but some.
The other thing is "anterior pelvic tilt." That can be inherent, or caused by, basically, sitting too much. The pelvic girdle tilts forward, which causes the spinal column to curve to compensate. The curve reduces the height of the column. The bottom vertebrae are basically interlocked together and move very little in relation to each other, so the "give" has to happen higher up.
Anterior pelvic tilt requires an X-ray for a certain diagnosis, but the symptom list is clear and almost universal. One of the more important ones has to do with leg motion. If you were to, say, lay back on a weight bench and put your feet on the floor, you’d probably feel a tug on the sides of your abdomen - if you were normal. With APT, you’d have problems getting your feet flat on the floor. I can’t come within six inches of the floor, even on tiptoe, and my lower back screams in pain when I try. So I bench press with my feet on the bench or on the pegs of the quad attachment on the front of the bench.
Many of the therapy exercises recommended for treatment of APT are similar to basic weightlifting or spinal kyphosis exercises. So, basically, I’ve been mitigating the APT for a couple of years now, and it is paying off.
I’m probably a third of the way through getting things fixed, so there’s more to be had.
TL;DR: exercise improves posture, which makes you taller. Q.E.D.