When you begin to take on races longer than 5k’s and train hard for 1.5+ hrs at a stretch, you will find that your performance is greatly boosted by taking in calories during your race/workout vs. water alone. This is true because when you work your muscles hard enough to require a fairly high proportion of glucose as fuel (vs. fat, which is a “slower” fuel), your stores run low – there is only so much glucose stored within each of your muscle cells, and after that they rely on glucose from your liver (which is also needed to power your brain) or protein breakdown to supply the quick energy they need. A little shot of sugar can bring back your motivation, energy level and even your ability to think better!
Endurance athletes are not all the same when it comes to fueling needs or their ability to use different types of fuels without suffering from GI upset. In general GI upset is more noticeable either for short, very intense efforts when digestion is very difficult or in very long events such as an Ironman where any number of things can go wrong with your fueling, hydration and electrolyte supplementation over the course of the day. Digestion and absorption rates are key. How quickly will the food leave your stomach? Is it absorbed effectively, or does it get fermented by your gut bacteria, resulting in gas? Macronutrient composition, the amount of water you drink along with the food (concentration), and how your gut works will all influence how well a particular fuel form or recipe will agree with you.
Ok, so what are the options, and what are they good for? We’ll start with products with the highest water content and move to lowest.
- Sports drinks. The ratio of carb grams to water milliliters for optimal absorption is thought to be 4:100 (4%) – Skratch Labs and Osmo Hydration products are made to be used in this way. This ratio comes out to 112.5 calories in a standard 24 oz bike bottle. In hot conditions it can be fairly easy to consume 24 or more ounces of fluid in an hour on a bike, allowing an athlete to fuel exclusively by this method if he/she requires only about 100 calories per hour. Otherwise a more concentrated solution (or the addition of solid food as Skratch recommends) will be required. Most bottled sports drinks, including Ironman Perform, are 6-8%, and of course powdered sports drink mix can be made to any concentration desired. Some sports drinks (Hammer Nutrition makes two of these) contain a small amount of protein – these are intended to be used for sessions lasting more than 2.5 hrs when your muscles may start to use amino acids as fuel in addition to glucose.
- Baby food in pouches. These little fruit puree pouches, which have a similar shape to gel packs, are pretty popular amongst endurance athletes! They contain only about 60 calories per pouch because of their water content, so plan on stuffing a fair number of them into your jersey pocket for a 2-3 hour event. You will want to wash them down with a bit of water. Be mindful of the macronutrient content of the one you choose – the more fat/protein/fiber in there, the longer it will sit in your stomach, so plan to minimize these. Also, baby food does not typically have sodium, so you will need to add this from another source (ie, salt tabs or sports drink) if it’s hot out and you’re sweating.
- Energy gels. Gels typically come 100 calories of easy-to-absorb carbs to a pack in a variety of flavors for fruit-lovers as well as fruit-haters. Peanut butter gels have popped up recently that taste just like PB from the jar. There are also gels made with chia seeds for a jammy texture (Huma), with a fig paste base (Reload), or just honey (Honey Stinger Classic). There’s pretty much something for everyone, and unlike sports drinks and baby food, it’s easy to find a gel with caffeine in it if you find that to be helpful while racing (I do!). Gels are concentrated, so they require water – not just to wash the stickiness out of your mouth or off your hand, but to help your gut absorb the carbs too. Don’t skimp! If you’re running, it’s best to finish consuming a gel just before you arrive at an aid station so you can toss the empty packet and grab some water to wash it down as you jog through. As an aid station volunteer I have seen folks wash a gel down with sports drink – I don’t recommend this! The gel is enough calories for one dose, and should be chased with plain water to avoid GI upset down the road.
- Energy chews. If you like gummy bears, energy chews are awesome. They are not sticky like gels, come in a variety of fruity flavors, and also can be found with and without caffeine for an extra boost. They can be a bit difficult to handle while riding (not all packaging is convenient to use), and when you’re working very hard, chewing can be difficult. But it’s also possible to stick one in your cheek like a chipmunk, and let it slowly dissolve. Just make sure you know how many chews you need to consume to reach 100 calories – it may be more than you think – and don’t forget to continue to drink water as you eat them.
- Regular food. If you’re riding your bike over long distances at low to moderate intensity, there’s no reason not to use real food as a fuel. Because you are staying aerobic and are not bouncing up and down like a runner, your gut can tolerate something besides liquids/gels, and chewing won’t interfere with your breathing. The gurus of what to eat on the bike are the Skratch Labs chefs, Biju Thomas and Allen Lim. I highly recommend their two cookbooks for great ideas for bike-friendly foods and how to wrap them for easy eating. These vary from rice balls to grits cakes to hand pies to waffles. If it’s got lotsa carbs and just a little fat, protein and fiber, it’s good on the bike! Remember to hydrate effectively when fueling with regular food. If you use a sports drink for this instead of plain water, remember to combine the calories from the drink and the food to find the total calories you can tolerate per hour at your desired level of intensity.
Consider the intensity of the event you are planning, and then pick a few options that might work for you. Try them out in training under conditions similar to your race (temperature, effort level, frequency of fueling/hydrating) and see how you feel both during and after the session. If you experience tiredness/sleepiness, you likely need more calories. If you feel full, you are either over-feeding or using a fuel with too much protein, fat or fiber, causing it to sit in your stomach for too long. If you get dehydrated or need to pee a lot, adjust your hydration plan.
Please add a comment about your favorite fuel(s) or a time when your choice of fueling didn't work for you like you expected!