I've started training for a cross country race in November which consists of 11 miles, is Isotonic for me?

I run approx. 2 – 3 miles every day or so and have only started. I hear the arguments for staying hydrated and to replace lost salts/vitamins etc… but then I hear the argument that I’m not an elite athlete and I’d just be wasting my money for something that I don’t need.

Can anyone add their personal expertise/knowledge on this please?

Thanks in advance.