I have always been aware that sports drinks help you replace potassium lost from exercise. But I also know that too much potassium in your bloodstream is not a good thing and bad for your heart. So can drinking too many sports drinks be dangerous for you? What would happen if a person drank a gallon of a sports drink a day for a month?
Sports drinks contain trivial amounts of potassium. For example, one US gallon of Gatorade contains 480 mg of potassium, which is roughly comparable to a single banana and much less than a sweet potato. The US RDA for potassium is 4700 mg per day, so you could safely drink 10 gallons per day if you consumed nothing else.
The dangers of potassium are vastly overstated, even by most medical professionals. If you have normal kidney function and you're not taking a small number of medications that cause potassium retention, it's actually extremely difficult to make yourself hyperkalemic by oral consumption.