While I can't attest to how well it works during an endurance event...I have a box of Reed's Ginger Candy Chews (can be found at Trader Joe's) that I keep on hand to help settle my stomach on occasion. According to the box, the ingredients are - sugar, ginger, tapioca starch...in that order. They have a fairly strong taste, IMO. Personally, I'd much rather have a glass of flat Ginger Ale to calm an upset tummy. I love Ginger Ale, but gave up drinking pop about 10 years ago...but I will allow myself a glass or two, around the holidays.