This person went from a 23-year career sitting at a desk to doing physical labor all day. Any physical labor is going to take a toll on someone in their 40s who hasn't been doing physical labor.
I have a lot of people in my extended social circle who are in physical labor jobs. Amazon Warehouse jobs are always viewed as the "easy" fallback option: Doesn't pay as well as the hard physical labor jobs, but it's also viewed as the safe, comfortable option. Obviously, someone coming from a 20-year desk job is going to have a different perspective when thrust into a job with any physical demands.