I'm 46. I haven't spent any money on gear, but I've been rucking for a year or so. I typically put ~25 pounds in a back pack and go for a hike. My preferred method of weight carrying is a couple of ziplocks full of sand in the laptop sleeve of a backpack, with the backpack cinched up pretty tight (chest strap, waist strap).
When I started, I had some ankle issues. That being said, I think that had more to do with poor walking (I overpronate) and a failure to stretch. I went to PT a couple of times and got some exercises, took a break from rucking for a month or two, and I've been good since.
I like it because it's something I can do outside, and I was taking a break from running (starting to ease back in, though). It's also a nice way to get some more exercise on a casual hike w/ my wife and daughter. I'm a fan!