I hunt mostly within an hour of home and within a mile of my truck...I don't pack heavy, I pack as light as possible. That being said, I take my full hydration bladder, 2 extra water bottles, small first aid kit (band aids and such) lunch or a snack, hot hands, doe bleet, estrous scent, and extra release. Knife also goes with but stays in my pocket, along with my cell phone in a plastic baggy and a trioxane bar incase shtf and I need to stay in the woods overnight or I get turned around and lost for the night.
My pack seldom weighs more than 20 or 30 pounds.
From my military experience though, I will tell you to make sure your pack is adjusted properly and you pack the heaviest weight to the top. Packing it to the bottom puts more strain on your back and shoulders and makes you work harder than you have to.
This is my experience with an 80 Lb ruck for 7 miles...and also a 50 lb ruck for 15+ miles. Take it for what you will.