Do Marathon Swimmers Eat & Drink During the Race? How!


One’s pre-race fuel (nutrition) is extremely important to their performance regardless of the distance. However, for those longer events, one will not only need pre-race fuel, but they will need to account for proper fueling (nutrition) during their race as well. 

Right about now you may be thinking something along the lines of, “Wait! I’ve been told since I was a kid that you shouldn’t swim within 30 minutes of eating (for a few reasons, I’m sure, but, namely, to avoid getting sick)”.But then, how is it possible to eat IN the water [while swimming]?”.  

This may have one pondering how exactly, then, do marathon/ultra-marathon (i.e., long- and ultra-distance) swimmers eat and drink during a race (i.e., while in the water)? And/or, are they even allowed to eat and drink during a race? 

Well, first, let’s start with the belief that one should not swim within 30 minutes of eating.

This is a myth. It’s a FALSE old wives’ tale

While some may experience adverse effects (i.e., feel sick) if they swim within 30 minutes of eating, this does not occur universally (i.e., this is not a hard and fast rule).  In fact, long- and ultra-distance swimmers (i.e., marathon and ultra-marathon swimmers) will take just seconds to refuel (eat/drink) while treading water (before going right back to swimming). 

Marathon (and ultra-marathon) swimmers should not (and really can’t afford to) fear eating during a race/while in the water. Rather, they are going to have to eat and drink (i.e., take in nutrients) throughout the race (i.e., while they’re swimming) to maintain a neutral energy output throughout the swimming event. 

One’s nutrition for a marathon swim will be a very personal matter. No one nutrition plan works for all swimmers across all long- and ultra-distance swimming events. Some swimmers will prefer solid foods (and can tolerate them) while others prefer liquids or gels because they are less dense and tend to be easier to digest (and, therefore, tend to be more tolerable by the stomach)


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Marathon/ultra-marathon (long- and ultra-distance) swimming expends large amounts of energy. As such, swimmers of such races are, typically, always functioning in a calorie deficit. Because of the demands of the activity, the human body is just not able to process enough calories per hour to keep up with replacing all the calories being used.

Check this post to find out How Many Calories Are Consumed In Triathlons; Why Is It Important? All Distances

However, through internal reserves and practice implementing a proper nutrition plan for races (i.e., fueling during the race/while swimming), the negative impact(s) that this calorie deficit produces can be lessened.  

When exactly one should schedule their “in-race feedings” will depend on how their body functions as well as the distance of the race. However, one’s body will typically have enough glycogen stores (i.e., carbs) to last 2 to 3 hours (this is, of course, dependent on energy expenditure during training and/or exercise just before the event). 

U.S. Masters Swimming recommends that for a 10K swim one should refuel (feed) halfway through the race with some type of liquid carbohydrates (though some may find for a race of 10K- roughly 2 hours- or less, they don’t need to fuel during the event). 

Many other marathon and ultra-marathon swimmers, particularly those swimming longer distances than 10K, professional and amateur, will refuel (feed) in intervals of 30 to 90 minutes throughout the race. And, yet, some will feed in intervals as often as every 15 to 45 minutes throughout the swim.

Again, everyone’s fueling requirements will differ

Find out more on the topic of Swim Marathon distances and check out our post How Long Is a Marathon & Ultramarathon Swim? (Distance & Duration)

No two swimmers are exactly the same. Thus, one will need to train the implementation of refueling (feeding) during a marathon (or ultra-marathon) swim. Both the type of nutrients (food/drink) that work best for you as well as the timing of fueling will need to be tested to determine what is best for you. 

So if swimmers are going to need to refuel (eat and drink) during their race, how exactly are they going to accomplish that? After all, they are in the water… how does one get food and drink to the swimmer? 

Well, there are a few different ways this can be done. Which one will be best for you will depend on what kind of support for the event you have as well as the event rules.   Though some events do not allow for any assistance (i.e., you would not be able to have someone in the water to provide food/drink), because of the demands of the event, most events will allow for support. 

How Is the Food Delivered?

So we established that long-distance swimmers (i.e. marathon/ultra-marathon swimmers) do in fact eat not only within 30 minutes of swimming but also while swimming. This helps them maintain proper nutrition that is then used to fuel their body during their race. This may have one wondering, how exactly do swimmers eat and drink while in the water? There are a few different ways this can be done, but the equipment needed is pretty much the same regardless

As such, there are a few different ways and pieces of equipment needed for your support team to get fuel/nutrients to you. The most common pieces of equipment needed for this are a telescoping (i.e., extendable) pole with some type of hook on its one end as well as some type of floating line and clips or tape (to secure food/drink containers to the line/pole). Other equipment may include a kayak, a larger boat, and/or a floating dock. 

Most often the support team is on a  floating dock, kayak, or larger boat (or sometimes just sanding if it’s shallow enough) in the water. They will then affix food and/or drink containers to the pole/floating line and pass them out to the swimmer. 

Some events will allow for, and some swimmers are comfortable with, feeding directly from their kayak or support boat in which case they will swim right up to the side (hull) of the boat or kayak and retrieve food/drink from there. 

It is worth noting that feeding from a kayak is often the quickest way to refuel during a marathon/ultra-marathon swim while feeding from a larger support boat tends to be much slower.  Furthermore,  the easiest way for the support team to get food/drink out to their swimmer,  which is often the slowest way for the swimmer, is via attaching a container to the floating line and telescoping pole and tossing it out to the swimmer, just a few feet in front of them. 

For those swimming at night, glow sticks or flashlights can be placed on bottles to make them more visible (i.e., easier to locate).  Just be very careful with flashlights- assure they are aimed at the container and turn them off as soon as the swimmer has the container. A Flashlight in a swimmer’s eyes can be temporarily blinding to them. 

(Source A)(Source B)(Source C)(Source D)

What Foods Should Swimmers Eat (& Avoid)?!

Nutrition is key when participating in sports. Especially extreme endurance sports such as marathon (or ultra-marathon) swimming. Earlier in this article, we dispelled the myth that one should not swim within 30 minutes of eating (i.e., this is a false old wives’ tale). 

In fact, to sustain energy levels throughout the swim one will need to eat and drink (refuel) properly not only in the days and hours leading up to the event but during the event (while swimming) as well.

With nutrition being a key factor in one’s performance, one may be wondering what foods should swimmers eat? … Are there foods that swimmers should avoid? 

In general, swimmers will want to consume carbohydrates (carbs) as well as electrolytes (and small amounts of lean protein never hurt either). What specifically one consumes will depend on what they prefer and tolerate. In other words, some will be able to tolerate solid food while others will not. Or, some may prefer gels/liquids over solid food. So, 

Ultimately, what, specifically, one opts to eat will be a matter of preference and tolerance

Some foods that swimmers will want to consider including in their nutrition plan for during their race are

  • Bananas 
  • Bars (Clif, Power, granola, or other energy bars) 
  • Energy chews (Shot Bloks)
  • Candy/Chocolate 
  • Flattened cola
  • Canned peaches (in syrup) 
  • Powders that dissolve in water (i.e., carb replacement drink mixes) 
  • Electrolyte replacement tabs or drinks 
  • Pretty much anything that you like and tolerate that provides you all of the things you need for optimal performance (and none of the things you don’t) 

Food Swimmers Should Avoid

Foods that swimmers will want to avoid when training for swims and on event day include 

  • Spicy foods 
  • Fatty foods 
  • Dairy products 
    • You’ll want to stay away from anything that causes stomach discomfort from GI issues such as bloating, cramps, and indigestion (all of which spicy and/or fatty foods, as well as dairy products, are infamous for contributing to). 
  • Foods high in fiber  
  • Foods high in sugar 
  • Sugary cereals 
  • [Sugary] Granola bars (the key here is the sugary ones. Nutritional granola bars are ok; sugary ones, not so much)
  • Caffeine 

The key will be balance and replenishment. One will want to keep their electrolytes and energy stores balanced throughout their race. This will take strategic replenishment.  It may take trial and error, but once you find the foods you like and tolerate implement them into your training and assure you have enough of them on hand for race day. (Source A)(Source B)(Source C

What Do Swimmers Eat Before a Marathon?

Not only is a swimmer’s nutrition important during their event (i.e., while they’re swimming), but before their event as well (i.e., before they even get in the water).  We’ve probably all heard about carb loading before endurance events/races. But, is that the best thing before a swimming race? What do (or, rather, should) swimmers eat before a [swimming] marathon (race)? 

Well, when thinking about pre-marathon (race) nutrition, one will want to consider not just the day of the event and the hours leading up to it, but the few days (3 or so) before the event as well. 

What to Eat 3 Days Before a Swim Marathon?

Concerning carb-loading, one will want to start this process about 3 days before their event. At this point, 3 days before your event, one can (and should) start incorporating more carbohydrates into their diet (i.e., incorporate more carbohydrates, more often in your meals and snacks).  Just be careful to not increase your intake of high fat and dairy products at the same time (i.e., avoid increasing your intake of creamy, buttery, or dairy-based sauces/products when increasing your carb intake). 

Also, while increasing your intake of carbs such as pasta and bread, don’t neglect your fruits and veggies. 

Fruits and veggies provide both carbs as well as other vital nutrients

While fruits and veggies are necessary, one will want to assure they are eaten cooked versus raw as it is easier to digest them this way. Also, one will want to stay away from “hard” veggies such as broccoli, carrots, and corn and opt for “watery” options like salad, squash, or zucchini. 

What to Eat 1 Day Before a Swim Marathon?

As marathon (race) day nears, as in the day before and the day of the race, one will want to begin to eat a little lighter than they were while carb loading. Particularly on the day of the race, one will want to eat light.

In other words, one will want nutrient-dense options that do not sit heavy in the stomach in the 24 hours leading up to the race.  Additionally, stick to foods that are easily (quickly) digested such as (non-sugary) cereal, fruit, or yogurt. 

What to Eat 2 to 4 Hours Before a Swim Marathon?

Anywhere from 2 to 4 hours before the start of one’s race, one will want to eat a meal that is high in carbs and low in fat and protein. The exact size of the meal will depend on factors such as one’s size/weight as well as how far in advance [of the race]  one is eating.

You’ll want to allow the body time to digest the meal.  Also, you’ll want to drink plenty of water during this time frame. One should aim for 16-20 ounces over the 2 to 4 hours before their race. Though, one should avoid things such as milk or acidic juices such as orange juice on race day. 

If your event is first thing in the morning, some options for one’s pre-race meal include

  • Instant oatmeal with fruit such as raisins or bananas (and cinnamon, if you like it) 
  • Fruit salad with yogurt and nuts (or seeds if you have a nut allergy) 
  • Toast with Peanut butter (or another nut/seed butter of choice) and banana
  • English muffin with jam or cheese
  • Scrambled egg with bagel 

If your race is after mid-day (i.e., lunchtime), you’ll want to opt for a hearty breakfast and then, in the couple hours before the event, opt for foods such as 

  • Turkey or Chicken sandwich
  • Peanut butter and jelly sandwich
  • Salad with a lean meat choice & cheese, and a roll
  • Pasta (but, you may want to avoid red/acidic sauces) 

What to Eat 60 to 30 Minutes Before a Swim Marathon?

Just before the start of the race- 30 minutes to an hour before its start- you’ll want to consume a 100-200 calorie snack that is carb-heavy such as an energy bar, dried fruit, or banana. Also in the hour before your race, you’ll want to consume 2 to 4 ounces of water or electrolyte replenishment drink every 10 to 20 minutes (you’re shooting for at least 8 ounces, and up to 20 ounces, within this hour). 


Overall, for the most part, it is best to not make drastic changes to your diet in the days leading up to your event. However, slightly increasing your carb intake (carb loading) while intaking a healthy amount of lean protein is acceptable. Also, one will want to stay away from foods that are high in fat, highly acidic, and dairy products in the days leading up to the race (as well as on race day). 

On the day of the event, it is generally recommended that one’s fluid intake be only water or electrolyte replenishment drinks. Their dinner the night before should be light and contain carbs from both grains and veggies as well as lean protein such as chicken or fish. Food intake on race day should be nutrient-dense, high in carbs, low in fat and protein, and digest easily/not sit heavily. 

Also, find out How (& How Much) Do Marathon Swimmers Rest or Sleep?

Again, one’s specific nutrition plan will depend on them [individually] and how their body utilizes the fuel (food and drink) provided. There is no magic nutrition plan that works for all swimmers across all swimming races. However, the above general guidelines should be able to help one plan their nutrition for optimal performance on race day. (Source A)(Source B)(Source C

Melissa Frank

My passion, outside of animals, is helping people and adding value to their lives…I strive to leave the world a little better than I woke to it each day. The first part of my career, for a total of about 15 years, was spent in the public safety field as a Volunteer Firefighter/EMT-B and 9-1-1 Operator. In 2019 I obtained my personal trainer certification (ACE certified) as well as many group fitness certifications and certification as a Corrective Exercise Specialist.

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