My mail carrier used to carry a leather bag with a strap over the shoulder that held at least 50lbs of mail, while he walked the neighborhood in 100+ degree heat.
Oh, and he hustled landscaping business for the weekends while he was on his route.
I’m a female, and at 54, was helping my youngest son deliver his morning papers.
I’d load up a bag on my back, and slung one across my shoulder, and carried newspapers...as many as I could pack in them so I’d have enough to finish the streets I did for him. And I never threw the papers. I placed them up on their porches in the door, or in their mail boxes. Climing up and down stairs, I lost more than 10 pounds doing that. Plus I worked a full 8+ hours as a Correctional Officer for NY State. At almost 72 now, I have trouble dragging my six-packs of soda and groceries up the stairs, but if I take it one step at a time (bad knees), I can get up them without being winded. Neither of my sons lives near me, so I have to do for myself. As my father used to say: “I’m in great shape...for the shape that I’m in.” :-)