Now that I'm double that age, the manual labor I've done like rewiring my house, installing all my own HVAC equipment, and all the yard work for a large property is much harder. I stay sore for days, and it's easy to push too hard to get something done and get injured or overwork my body to where my heart rate stays elevated for hours.
There's something to be said for working with your brain. The worst days dealing with idiot product management and never-ending Jira tickets don't compare to unloading a truck in a hot warehouse or kneeling in a crawlspace for hours re-piping a sewer line.