I'm continuing my Fuel Your Workout blog series by exploring what to eat during long runs, which is anything >60-90 minutes. These nutrition strategies also apply to triathletes, cyclists, swimmers, Peloton enthusiasts, and other athletes. There may be logistical differences from one sport to the next, but the fueling principles remain the same.
Fueling during exercise is a huge topic, and this post is by no means comprehensive (we'd be here forever). Here's what I'm covering:
If you missed my related posts in this series, here ya go: What to Eat Before a Short Run, What to Eat before a Long Run, and Hydration for Endurance Athletes.
Fuel During All Long Runs
You should fuel during all of your long runs, no matter how old or fast you are, or if you're training for an event or not. Your body only knows the work you're having it do, and you need to fuel it accordingly.
Even if you're "only" running for 1-2 hours? Yes, and here's why:
You'll perform better during the session: You have limited carb stores (our preferred fuel source), and after 90min is when you need outside sources of energy (carbs) to keep feeling good while you run.
Short long runs are great opportunities to practice fueling strategies and train the gut. If you have an endurance event coming up, you should take advantage of all longer sessions to nail down your fueling plan!
Just because you can, doesn't mean you should: Can you run for 1-2 hours (or more) without calories and/or fluids? I'm sure you can. But you don't get a medal for running fasted.
Training without carbs has negative health and performance consequences, including decreased training intensity, carb oxidation, race-day performance, and immune function, and increased protein breakdown. No thanks!
Keep the bigger nutrition picture in mind: Endurance athletes have really high energy and nutrition needs. It's hard enough as it is to meet these demands, so why put yourself into an even deeper nutrition hole by intentionally skipping your fueling?
Nearly everyone I work with prioritizes their training but is not fueling enough, both during and outside of exercise. Sometimes this is intentional, sometimes not.
Either way, here's the hard truth: If you're not able to eat enough to support your body's health, then you shouldn't be exercising as much as you do.
I know figuring all of this out can be overwhelming and confusing (don't worry - I'm here to help with that). Please don't wait for a DNF, injury, or another negative health outcome to make nutrition top priority!
What to Eat During Long Runs: General Tips
Keep these general tips in mind when fueling your long runs / other endurance activities:
Start early and fuel consistently: Most of my athletes practice the popular strategy of having a gel or something else with 20-30g of easily digestible carbs 5-10min before a long training session or race. That fuels the first chunk of exercise. Then take your next gel or whatever you are using 15-30min later.
Fuel by time, not by distance: Fueling goals are mostly by the hour, so it doesn't make sense to fuel every x number of miles. Miles are helpful when it comes to timing fueling with aid stations, but it's harder to fuel consistently when the terrain isn't flat or your pace changes for other reasons.
Focus primarily on easy to digest carbs: Carbs, along with fluid and electrolytes, are the main components of a nutrition plan. There are TONS of sports products, foods, and fluids available in today's market. Experiment with different things to figure out what you like or at least tolerate the best.
Ultramarathons require a different fueling approach: You cannot fuel an ultramarathon the same way you'd fuel a marathon. In addition to carbs/fluids/salts, ultrarunners need small amounts of protein and as tolerated or desired, a little fat. It's key to have a variety of tastes, textures, and solid/liquid fueling options. More frequent fueling (e.g. every 15min) helps keep the gut happy.
Don't forget about logistics: Consider how you will carry what you need, and if you have the right gear for your fueling plan (handheld, hydration vest, shorts with pockets etc). If you're training for an event, what is offered and allowed on the course? Do you get drop bags and/or will you have crew supporting you? Research all relevant details in advance, so you can practice your fueling strategies.
There's no one "right" way to fuel: There are many pathways towards the same goal, which is fueling in a way that feels good to YOU. There's nothing wrong with trying something because a friend or influencer recomends it, but just remember that your taste preferences, tolerance, sweat rate, salt losses, etc are unique to you. Your challenge is to discover the secret sauce to performing your best.
At the end of the day, fueling is an investment in your performance and allows you to have FUN. You want to reach your full potential, not scrape by with the bare minimum, so you can keep doing the sport that you enjoy for as long as possible!
Hydration Goals During Long Runs
Both fluid and sodium needs vary dramatically from one athlete to the next. I cover this topic in great detail in Hydration for Endurance Athletes. That post will teach you how to individualize your hydration plan for all exercise, including long runs.
Fueling During Long Runs: Carb Guidelines
Here are some research-based carb guidelines that you can use for long runs as well as shorter workouts and races:
During shorter sessions and races <45min, you don't need carbs. As I covered in What to Eat Before a Long Run, begin your session well-fueled and hydrated. Then, you can drink water and/or electrolytes during exercise as needed.
During high intensity exercise 45-75min (e.g. speed session or race), add small amounts of carbs while running. This could be sips of a sports drink, some chews, or other easily consumed carbs.
During exercise lasting 1-2.5 hours (e.g. shorter long runs or races), aim for 30-60g/hr of carbs. If you're training for a longer event, such as an ultra, practice consuming at least 60g/hr of carbs as well as other parts of your fueling plan (e.g. solid foods, protein etc) to work on your gut training.
During endurance exercise over 2.5-3hrs, aim for 60-90+g/hr of carbs. Higher intakes of carbs are associated with better performance, but you have to consider GI tolerance. Be cautious about going >90g/hr unless you've established that you can take this in for long periods of time.
If you're a cyclist, you may tolerate a higher number of carbs, especially in liquid form (up to 120g/hr). If you're a triathlete, you can increase carb intake on the bike, but you may need to reduce how much you're consuming towards the end of the bike portion and during the run. As always, experiment and see what feels and works best.
You may notice that there is no relationship between body weight and recommended carbohydrate intake. Meaning, these guidelines are grams/hr not grams/kg/hr.
That is because sugar absorption in the gut is limited by certain transporters. The transporter for glucose can handle about 1g of glucose/min, or 60g/hour. This increases when mixed carb sources are used (like glucose or maltodextrin and fructose) because we add another transporter.
Think of a river with one bridge - things get pretty backed up when everyone is trying to get across! If you add a second bridge, the traffic flows more smoothly. So if you see multiple sugars on an ingredient list, that is one reason why.
Fueling During Long Runs: Protein and Fat
As mentioned above, ultra endurance distances (e.g. >3-4hr) require a different approach to fueling. This makes sense - when you're out exercising for hours and hours, you're missing meals and snacks and carbs alone won't cut it. Some athletes get hungry, or at least need a variety of products and foods to continue eating and feeling good.
I'm usually adding protein (and as tolerated, fat) to race plans for my ultrarunners, endurance cyclists, and long course triathletes. Marathon and half marathon runners are fine sticking to carbs, fluids and salts.
It’s unclear if adding protein during exercise actually improves performance, but it does improve protein balance in the body because you're not completely skipping the protein that would normally be consumed. Anecdotally, many athletes feel better in terms of hunger and gut tolerance when including protein.
This International Society of Sports Nutrition Position Stand recommends an intake of 5-10g of protein per hour, or 20-30g every 3 hours, which is what I typically suggest to my clients. You can reach this goal by eating bars or other solid foods, or drinking recovery drinks, which I reference more below.
There are no specific intake guidelines for fat. But that doesn't mean ultra endurance athletes shouldn't consume it.
Here are a few things to keep in mind when experimenting with fat-containing foods and products during a run:
Fat takes longer to digest, which means it may be less well tolerated, especially while running. Start with very small amounts, and increase as tolerated/desired.
Your need/desire for fat may increase as your time exercising increases. Make sure you're not having so much fat that you are unable to meet your carb goals!
Fat is very caloric, which is a good thing when you're burning tons of energy for many hours.
Foods with fats are usually a welcome flavor change from sweet gels and drinks, and may help you continue to eat / get calories in.
Foods like peanut butter in a PB&J, the cheese in a quesadilla, or the oil in potato chips are some popular ways to get fats in. Some athletes may also have full meals, containing all three macronutrients.
Common Fueling Options: Sports Products
Sports products include things like gels, chews, waffles, bars, sports drinks, and electrolyte supplements. They are convenient and provide easy-to-digest carbs, electrolytes, fluids, and in some cases, proteins and fats.
Here are some popular gels and chews, which I've organized by carb content:
Gels and chews contain mostly carbs, but they vary greatly in how many they contain. They also have different tastes, textures, and electrolyte profiles.
Some gels are very thick and sweet (e.g. GU), while others are thinner and less sweet (e.g. SIS). Some gels are flavored, while others like Maurten and Precision are not. Whatever your preferences are, you should be able to find something that works with so many options!
Here are some popular waffles and bars, organized by carb content:
Waffles tend to be mostly carbs. Some bars (like Skratch and Maurten) lean heavily towards carbs, while others also contain a good amount of protein and in some cases fat. Some bars (not pictured) are lower in carbs and are not appropriate for fueling.
For use during exercise, choose bars with at least 20-30g carbs, lower fat (<10g), and moderate protein (e.g. 5-10g) to digest more easily. Bars are very handy in ultra-endurance activities.
Here are some electrolyte products and sports drinks, organized by carb content:
Sports drinks vary dramatically in carb (and salt) content. There are lower to moderate carb options (e.g. Precision, Nuun endurance, Maurten 160, Skratch Sport, Tailwind) as well as very high carb options (e.g. Maurten 320, Skratch high carb). Note that these carb amounts are per serving.
Electrolyte supplements provide very little if any carbs and primarily provide salts (e.g. LMNT, Nuun Sport, Skratch Everyday Hydration mix, etc). If you use these, make sure you're getting enough carbs elsewhere.
Recovery drinks, which have protein, carbs and electrolytes, are handy after exercise but also during ultra endurance sports like ultra running, long course triathlon, cycling etc. Tailwind and Skratch both have good prodcuts in this category.
I know it can be confusing with so many products available, but it's also great because there is something for everyone out there. If you're feeling overwhelmed by all the choices, try narrowing things down based on your sodium and fluid requirements. Then you can decide based on taste and tolerance.
Read Hydration for Endurance Athletes to see similar product breakdowns but for sodium.
Common Fueling Options: Foods
Many people use a combo of sports products and foods when it comes to fueling, especially in ultra endurance activities. That's in part due to flavor fatigue, but also because you need more than just carbs when you're exercising for much longer periods of time.
Here are some of the most common foods and fluids that I see in my practice and at the many endurance races I've attended:
Sweet:
Fig bars, applesauce, smoothie pouches (e.g. Noka), gummies, coke, gingerale, cookies, dates, PB&J, watermelon/other fruit
Salty/savory:
Pretzels, chips, mashed potatoes, quesadilla, turkey sandwich, salted PB sandwich, plain bagel, broth, chicken noodle soup, rice balls, boiled potatoes with salt
These items tend to be more prevalent at longer duration events like ultramarathons, long-course triathlons and cycling events, but I've had the occasional road marathoner come to me wanting real food instead of gels and we've made it work.
Some of these options purely provide carbs like gummies, coke, fig bars, and pretzels. Other foods have a bit more substance with protein and/or fat, which is important when an athlete is out for longer periods of time and is missing meals and snacks.
Fueling in Different Conditions
Different environmental conditions affect how you should fuel during your long runs.
In the heat, appetite can get thrown off and you need to make sure you stay on top of your hydration so that GI issues don't occur and throw off your ability to fuel. You may find that liquids are the easiest way get carbs in, or maybe refreshing foods like watermelon.
This is where pre-exercise fluid and carbs is crucial, so you start your training session or race in a well-hydrated state with high carb availability. That way, in case things do go a bit sideways during your training session or event, you have some buffer.
With cold weather, in addition to decreased thirst sensation which may lead to fewer calories coming from fluids, you also have the logistical challenges of fueling. Running can be slightly easier compared to winter sports such as skiing, as your hands are likely free. That said, you need to consider terrain and how cold it is.
If it's below freezing, you need to worry about your nutrition freezing. If you want to use things like chews and gels, make sure you keep them close to your core, and inside your layers so that they stay warm and unfrozen. You can also insulate your fluids, and choose concentrated fluids like Skratch super high carb or Maurten, which are less likely to freeze. Instead of gels, try taking things like dense cookies.
At high altitude, which is anything above 8,000ft, you have higher fluid and carb needs. At the same time, people often struggle to get fuel in due to increased GI issues. The best strategy is to practice taking smaller, more frequent, sips and bites.
This could be 1 chew instead of two or three - maybe you're even sucking on it for awhile. Small sips of sports drink. Or little sips of a gel or a bite of a bar. If you live at sea level, practice eating and drinking in smaller amounts but more frequently so it feels more natural.
Wrapping it All Up
You need to eat and hydrate during all long runs to maximize both performance and health. Hopefully this post has taught you that your fueling plan must be individualized to your unique needs, tolerances, and what type of run you are doing (think terrain, weather, distance, etc).
Set specific intake goals for carbs (g/hr), fluids (oz/hr), and sodium (mg/L), plus protein if relevant, and practice all fueling strategies in training. There are tons of fueling options, and with enough experimentation and practice, you will find the ones that work well for you!
Additional Resources on This Topic
For ultrarunners: Listen to Performance Nutrition for Ultrarunners - this episode will teach you how to fuel specifically during an ultramarathon, with tons of tips and tricks.
For triathletes: Listen to Nutrition for Triathlon - this episode addresses nutrition challenges that are unique to the 70.3 and 140.6 distances, and teaches you how to overcome them.
If you'd like this blog in a more condensed, digital download form, check out my Fueling During Exercise Mini Guide.
Lastly, if you found this post helpful, you will love my self-paced course Peak Performance for Endurance Athletes: Your Ultimate Guide to Strategic Fueling. This 7-part series is packed with evidence based, easy to understand information with tons of visuals covering everyday nutrition, hydration, intraworkout fueling, training the gut, performance and micronutrient supplementation, and preparing for race day.
Preview the course, the full curriculum, and get all your questions answered by visiting my Teachable School.
Questions? Comment below or get in touch.