This article raises alot of concerns for hunter to make sure we know what we are capable of . Hunting smarter not harder as we age is also a good strategy 
. I know myself the days of dragging a deer for a mile or even half a mile are over. Being a safety Consultant I urge each hunter on here to make sure that a good plan of retreival is in place to conquer the task of removing that deer to the pickup or the hood of your car( to each their own)
. A 4 wheeler and a drag rope ,or like @shooterrex a JD tractor , a horse ( which my dad did on many occasions ) Just dont place yourself in a position of overexertion and push your body beyond its current limits. As we age physical abilities deteriorate over time and a good walking and workout program and a Health checkup can go along ways in protecting your life while retreiving that once in a lifetime trophy or that Freezer meat.
Always used 4 wheelers to get em back to camp. id drag them to where i could drive the wheeler too and load it up and take it to camp to hang up and gut. sometimes it was a short drag and sometimes not. bucks were always a lot easier to drag cause you could grab the horns. does you have to drag by the legs and those legs get slippery after a while. i never used one of those drag harnesses.
Weight is but one part, adrenaline before the kill raises blood pressure, then begun gutting and dragging, all adds up, now, if we ate more venison, less bacon and greasy burgers, might be less of an issue.
The sonic garlic bacon cheesburger is to die for. 
I have a drag rope with a built in handle it is the berries. And I drag to any flat place I can get the Jeep to and then it goes in the bed. Now I have a winch too so no more dragging up hills from now on.
This is the reason i won’t hunt or fish alone. I don’t even like going to the gun range alone, just in case of a negligent discharge.
Doesn’t mean it won’t happen in 2023 9or 2022) at an IDPA at the range I shoot at, one guy left his squad to go to the restroom, took 20 minutes for them to wonder where he was. He was face down in a puddle, heart failure.
I used my John Deere 1025R to not only retrieve my deer this year, but I also skinned it using the tractor and the “golf ball method.”
You don’t stop hunting when you get old. You get old when you stop hunting.
Rather die dragging a deer than on a morphine drip in palliative care with someone in the bed beside me watching Oprah on TV with the volume up.