My rides are normally 40 miles, 2 plus hours and about two thirds in I start to fade a bit so consume a GU along with a drink. Within a few minutes my energy level picks up and I finish my rides at ease without cramping. In the heat of summer I will consume two at 40 minute intervals. Have tried all flavors and prefer the peanut butter's true flavour and easily digestible. Last year I rode 6,200 miles on my Merlin with Shimano DI2 components and turned 80.
I use Gu before my early morning tempo runs as a quick source of fuel. I also use them on my long runs. I like the consisteny of Gu better than all other competitors and it seems to give me the best boost of energy.
Very tasty and easy on the gut, but too thick for waterless consumption and too light on salt for replenishment.
