For hydration, my favorite is home brew (plus I'm cheap).
I make old fashioned Kool-Aid (w/ sugar) and throw in lite salt for electrolytes.
You can vary the amounts of Kool-Aid, sugar & salt to suit your needs & taste,
but I like to add more water than per the Kool-Aid instructions.
I sweat a lot & need salt, and I use about 1-1/2 teaspoon salt per cup of sugar.
I've considered adding a little powdered protein, but I'm afraid that will spoil the taste.
Orange Kool-Aid is my favorite, but there are numerous flavors & brands you can try.