Sports drinks are probably a topic for the training and nutrition subforum. There’s a million of them. Some have more science behind them than others. I ordered a tub of HEED a few years ago and haven’t made it through yet. It has xylitol and maltodextrin, which burn slower than sugar. That’s good for me since I’m on a medication that exacerbates sugar crashes. But it’s not tasty enough I crave it. As for what you can find at the grocery store and pack light, Gatorade at least still comes in powder too.