Out here in the scrub of Victoria, where I live in my tent, I have my weights. Logs, boulders, tree trunks, all the goodness the bush can provide. Even though I am in my 70s, I still pump, not iron, but wood and rock, every day, along with martial arts, quarter staff training. I have long felt that merely doing as routine a walk around the block with the dog and/or wifey, is good, but not enough. And my intuitions have been confirmed by recently published research that indicates that not only can older people increase their strength, and bone density, by weight training, but weight training makes the connections between nerves and muscles stronger, protecting the motor neurons in the spinal cord. There is also research indicating that weight training can have a direct benefit on slowing down the inevitable cognitive decline associated with old age. But, anyone thinking of lifting, should see their trusty, highly ethical doctor first, and get a check-up.
https://www.sciencealert.com/weight-lifting-in-old-age-does-more-than-just-keep-your-muscles-strong