How much do you think Sam can bench press?

I'm new to the game and idk if there's an in-game reason but it's kind of insane that he can even carry this much cargo lmfao

On another note any none spolery tips would be appreciated I'm playing completely blind and also playing offline and I understand it's harder this way but I don't mind. I am currently in chapter 2 I'm like 15 hours in I feel like maybe I'm taking a lot longer than the average playthrough?