It's mild tasting, easy on the gut and vegan, with a neutral flavour you won't get sick of. Simply mix, sip and enjoy a boost when you're on the move. Talk Nerdy To Me The electrolytes in Fuel X Endurance are formulated to replace everything you lose during endurance pursuits so you stay energised, hydrated and replenished when training or racing. This all-natural product has no added sweeteners and is easily and quickly absorbed with minimal effect on the digestive system.