These are a tasty, healthy snack for anyone, not just endurance athletes (and we love our snacks). I found this recipe on the web years ago, and made some tweaks to increase the protein and fiber, and lower the sugar and fat. Instead of canned pumpkin, try leftover cooked sweet-potato, and really pile it in. You can add dried fruit or nuts if you like. I enjoy these muffins warm from the oven, and spread with a little apple butter. The recipe makes almost 2 dozen, and they freeze really well.