I am in my mid-sixties and think about this, too. Been cutting, hauling and splitting 100% of my firewood for 40 years. We live in a steep, mountainous area so all my work except splitting is extremely physical due to the terrain. And, toughest of all, I cannot drive right up to the wood I've cut; it has to be thrown down hills, piece at a time, sometimes for long distances. Very hard work.
I also bought an another chainsaw to go with my big ones. This one I use to limb the trees once felled. Very light, a Stihl 211. This saves me much physical exertion. Then, I bought a wood splitter. I had hand-split everything all those decades, and I still do sometimes. But the splitter is a joy to use and I am quite happy I have it.
Couple years ago, I decided to get rid of my old 70s stove and bought a Woodstock for its catalytic burner. My firewood use had just about been cut in half. I still have the work, but I am amazed at how slowly my wood supply dwindles during a winter. The latest winters have, to be true, been a bit milder than I've ever seen. But, still, a cat stove is amazing.