Hdl and ldl levels are used to measure the amount of water in your shoe. If youre wearing a shoe with a ldl rating, then youll be able to run faster than if youre wearing a shoe with a hdl rating. You can also use hdl or ldl ratings to determine how much water your shoe will hold. The hdl rating is the amount of water in the shoe, while the ldlt rating is the amount of water in the shoe. For example, if you wear a shoe with a hdl rating of 4, then it will take 4 ounces of water to hold that same amount of water in your shoe. If you run with a hdl rating of 3, then youll need to carry 4 ounces of water in your shoes. If you run with a ldlt rating of 2 ounces, then it will take 2 ounces of water to hold that same amount of water in your shoes.