You can not physically carry around lots of things without getting tired.
You can carry it on a cart, that way you don't have to exert yourself that much. Our muscles can only take so much stress
before they get tired. Working out
may increase your stamina, but even then you will have a limit that you can not go over.
Endurance - can be your friend though - slowly increasing the amount can help.
Answer assisted by Saurabh Bajpai, Medical Student