Item Burden

From Wikidsouls

Item burden is the total about of weight you can carry (hold in your inventory). Your max weight can be increased by leveling the Vitality stat. Item burden does not effect your move speed or stamina drain. To avoid a high Item Burden, make sure to leave any equipment and items you don't regularly use with Stockpile Thomas. Also, a Ring Of Herculean Strength will increase you Item Burden significantly. It's usually smart to keep one of these on you whenever you go into a dungeon, in case you end up finding more loot then you Item Burden will allow you to carry.