When it comes to long-distance cycling and triathlon, or any other endurance event lasting many hours, hydration and nutrition are key. The most convenient way to get the calories, sodium, amino acids, and other nutritional elements you'll need to keep going strong in the saddle is via prepackaged energy bars and gels. One of the original products was Powerbar, which is now available in more than 10 flavors. While Powerbar packed all the nutrition you need into one bar, containing about 250 calories, it didn't appear to be real food to athletes. Several manufacturers, such as Clif Bar, arrived on the scene to create energy bars to compete. As well, culinary entrepreneurs have formulated many types of energy bars in their own kitchens. Now, the selection of energy bars is wide - there are at least 10 major manufacturer choices, and you can choose your favorite energy bar based on the core ingredients you want: maltodextrin, sucrose, cane sugar, soy protein, etc. In the triathlon world, some triathletes will place energy bars directly on their bikes for easy transport and easy access during races. Most energy bars are packaged for easy opening while you're riding, and some of the packaging itself is biodegradable, just in case it ends up on the side of the road. When it comes to energy gels, one thing most have in common is sizing. Each packet of gel is physically about the same size and will contain approximately 100 calories. Most gels use maltodextrin as the main ingredient, since it's a slow burning fuel source for glycogen. From there, the formulations vary widely, especially as regards sodium, potassium, magnesium, amino acids, and several other minerals. Like energy bars, these packaged gels come in a plethora of flavors: you name it, you'll find it. All the fruits of the orchard, all the colors of the rainbow, many based on spices, and even "just plain", a popular GU flavor. Remarkably, cyclists and triathletes often hone in on their exact favorite brand of energy gel based on digestibility as the main criteria. That is to say, you probably should try out several different brands and even different flavors within a brand to find out which ones you can stomach best during training and especially on race day. When it comes to Ironman racing, most triathletes use a combination of energy bars and gels, though leaning towards primarily gels. The reason is that energy bars sometimes contain fiber that isn't necessary on race day; on the other hand, eating an energy bar is like eating real food, which is something triathletes want when they are 90 miles into the bike leg. Gels are handy because they are easy to eat and it's easy to keep track of the calorie count. As well, there is an nutritional argument that only carbohydrates are needed during endurance races, that protein and fat are really not necessary, and so gels have remained a popular and easy way to stay fueled with just the basics during racing. Popular brands of energy bars and gels include: Hammer Nutrition, Clif Bar, GU, Power Bar, Honey Stinger, Clifshot, and Nuun. A recent addition in this category is gel blocks, which are similar to gummy bears, with Clif Bloks being a popular choice.