There is a strong genetic component to osteoporosis, as far as I know. My grandfather, mother and aunt all had it, so I was aware of it from a relatively young age.
There was a clinical trial going on in the college where I used to work, involving the effect of weight bearing exercise on bone strength. I signed up for it and had a Dexa scan at the beginning and end of the year long programme. The exercise was quite intense - 2 supervised sessions per week and one done independently. Some involved steps, jumping etc and some with knee problems dropped out early. (Definitely wouldn't suit anyone with prolapse). I stuck with it and in the end, the Dexa showed my bones had improved. However, I didn't keep it up, but asked my doctor to refer me for scans every 2 - 3 years. I took the aldronic acid for a few years, with no problems, but read it was not good to continue long term. I've managed to maintain my bones reasonably - some osteopenia, but not getting worse.
I'll have another scan shortly and depending on results, might opt for the 6 monthly injection - denosumab, brand name Prolia. I also take calcium+vit D.
My story shows that weight bearing exercise can improve bones for some people, but if you've inherited the tendency for osteoporosis, get regular scans and take whatever drugs are offered!