Category Archives: Feeding strategies

Feeding during long or Open Water swims

HOW TO: Sample marathon swim feed schedule (MIMS)

(Apologies to the subscribers who got three unfinished versions of this on Saturday. I was sick for a few days and should have stayed away from the computer, especially after the first mistaken post).

Feed schedules for long swims are often discussed amongst swimmers, but for some reason we are reticent to show them, possibly for fear of criticism.

I can’t claim that any one schedule is definitely the best, only that there are schedules that work and schedules that don’t work and those may be different for different people. Schedules will also be different depending on expected event duration and water and air temperature.

The important questions you must decide are:

  • Do you need hot or cold feeds?
  • What is your feed interval? (Is it the same the whole way through from the start?)
  • Are you planning to take an electrolyte or other break from carb feeds?
  • Do you need painkillers or any medication on the schedule?
  • Do you need or want irregular solid foods or liquids (soup, fruit, tee, coffee, chocolate etc)?
I was asked what I meant by irregular foods. I mean the treats that swimmers often take to reduce salt build up in the mouth, as a comfort food, as something to look forward to in x number of feed’s time, or simply as a break from carbs. Freda Streeter, as you saw in the swim checklist, recommends Milky Ways and Cadbury’s Chocolate Rolls. Finbarr likes Fry’s Turkish Delight, I like tinned peaches, etc.

Here’s my pretty straightforward MIMS feed schedule though, where I was keeping it simple, not even a 2:1 mouthwash.


Let feeds sit in sun for an hour. (This was an instruction to Dee beforehand. In reality it was too warm, and cold feeds, a novelty to me, would have been best for the day)

End of 1st hour     Maxim       700ml

End of 2nd hour    Maxim       700ml

2:30                       Maxim       350ml from here

3:00                       Maxim

3:30                       Maxim

4:00 Dissolved Electrolyte with Ibuprofen, 700 ml.  Mix in advance, let settle

Feed every 20 minutes from here

4:20    Maxim

4:40    Maxim

5.00    Maxim

5:20    Maxim

5:40    Maxim

6:00    Electrolyte dissolved, Mix in advance, let settle

6:20    Maxim

6:40    Maxim with Ibuprofen

7:00    Maxim

7:20    Maxim

7:40    Maxim

8:00    Electrolyte dissolved, Mix in advance, let settle

8:20    Maxim

8:40    Maxim

9:00    Maxim

9:20    Maxim, only if more than 10 mins from end


So the pattern is five Maxim feeds before taking a break and having an electrolyte, with prophylactic painkillers taken twice, just in case, especially since I’d been having shoulder pains for three weeks beforehand. The electrolytes were a larger volume, 750ml and on the third I was only able to take half, despite ongoing dehydration problems, (more details on that in the MIMS swim report). As usual I’d been off caffeine for months beforehand and the Zyn electrolyte was one with added caffeine (20mg), not enough as it turned out as I felt no coffee kick at all, especially at the total amount of caffeine ingested was only about 50mg, about half a cup of standard coffee, which I hadn’t calculated properly beforehand, another lesson. We had actually taken a flask of coffee but with the heat decided against it. A bottle of cold coffee with the electrolyte added would have been the solution, but I didn’t think of this during the swim.

Related articles


HOW TO: Important factors in marathon swim feeding

Evan did a great 4-part series on open water marathon feeding and nutrition. I’ve covered the possible use of Choline supplementation and I’ve a long-standing request in with a friend for a guest post on the subject of further supplementation.

Given some questions that have arisen though, it seems we haven’t covered enough of the subject. It struck me that we hadn’t covered mechanics and some of the complicating factors.

Let’s start with a reminder:

The most important thing is: Feeding is different for everyone.

Feeding is not diet or general nutrition, but the process of taking in nutrition/food for energy during a long swim. It’s a long and complex subject which entertains and causes endless discussion amongst marathon swimmers.

The next most thing, the marathon swimming motto: Practice everything.

  • First, when do you have to feed?

You can generally assume that you have enough glycogen in your body to last from two to three hours. (Contingent on not having depleted it in training or recent exercise).

So for a swim or race under two hours, you probably don’t need to feed.

Swims where feeding is necessary dictate practice and experience.

FINA marathoners will probably feed small amount every 10 minutes from a plastic cup. This technique was pioneered by Peggy Dean and the US team in the 80’s. The rest of us tend to feed at intervals from 15 minutes to 45 minutes. (I feed at thirty minutes). But this MUST be tested, everyone’s requirements are different.

Also, you may not need or want to start on intervals right from the start of a marathon swim. it’s quite common that swimmers will feed hourly for the first two OR three hours and then switch to their shorter interval. Once again, I cannot tell you what those times will be for you. The four to eight-hour swims that we do in Sandycove give us the advantage to test these factors. It is another reason faking a qualifying swim makes someone a fool to a more experienced swimmer.

  • Second – what do you feed on?

For most swimmers, the primary fuel is maltodextrin, pure carbs,, as Evan has covered in detail. (Not however glucose). The product name isn’t important though Maxim is by far the most popular for distance swimmers as it has no taste and can be added to any food or drink. It’s a 100% maltodextrin. High5 or similar are carbs with a protein mix in a 4:1 ration, scientifically shown to be more effective in metabolization but has proven to be a problem for many swimmers (e.g. me) in distance sea swimming for a few reasons: (salt intake, prone position, soya protein metabolization).

Again, there are many exceptions. Some swimmers like gel pack (like GU) others won’t touch them, as they can be useless because they require a separate liquid intake, and the salt intake during a swim can make them useless or cause exceptional bloating or vomiting. Some English Channel Pilots only believe in/use Maxim.  Many swimmers have no problem with a 4:1 protein/carb mix, (I am not one, like a lot of swimmers, I found after about four to five hours with it I am no longer able to digest). Some swimmers forego these methods and swim on solid food (Penny Palfrey used dilute porridge).

  • How do you feed?

For myself for swims, I attach a D-clip to the bottle itself (whether by tape, string or lid attachment), and then the line attached to the clip, rather than tying a line to a bottle directly, as having multiple changeable bottles allows more flexibility.

Alan Clack’s feed pole

Feed (dolly) poles (typically a wooden brush handle … ) have a hook or holder on the end, which hand a cup or bottle to the swimmer. The one on the left is one used by Alan Clack on a 10k Lac d’Archambeau swim last year.  Poles are good in flat water but they are less flexible in bad weather as they require a fixed distance to the swimmer. If using a pole the swimmer must not grab the pole itself. I’ve also seen (and used) a telescopic fishing pole but the line is too light and too easily tangled.

Or simply a bottle dropped on a rope. The problem with this is knots and retracting the line (this was a mistake I hadn’t considered in the Channel).  A solution I’ve seen and really liked is a simple traditional-type kite reel (usually made of plastic).

My subsequent solution … A retractable dog-leash, my choice for future swims. So much easier for the crew.

Retractable Dog leash

  • Feed containers

Many experienced swimmers will often only use a container or bottle with particular features. I’ve written before about the God Bottle. This is not necessarily a minor concern as using a wrong bottle type for a swimmer can lead to salt water or air ingestion, both significant is you are swimming for more than 6 or 8 hours. Gábor used a narrow neck squeezy sports bottle, as that was what he used in training and practised with. (I must have a wide neck bottle… However some swimmers just don’t care or don’t have an issue).

Mike Oram, famous English Channel pilot, prefers plastic milk cartons, which have a wide neck and a handle to attack the line, and are easily replaced. Liam Maher added the point that it might be good idea to collect your milk lids for a week before hand, so the crew have more lids than bottles, that way the swimmer isn’t focused on trying to replace the lid.

Stephen Redmond feeding in Catalina

Stephen Redmond  uses a twin bottle approach to swimming: A standard squeezy bottle and a shaker bottle, taped together but in opposite directions for easier access!

  • Is it a cold water swim?

You must consider the water temperature: Should the food be warm or cold? Most Channel swims are cold or cool water so warm feeds are essential. But that can require  a lot of warm water. Your pilot may have a galley where water can be heated, but in rough weather this isn’t easy. One solution to this, just in case, is to bring a thermos (or many) of hot water. Pre-mix the feed to double concentration (half volume) and top up with hot water. The crew MUST be careful not to burn the swimmer, which can happen easily as the swimmer’s mouth will cool down during a swim. Bringing a thermos also frees up the crew to look after you.

  • Will you need/use electrolytes?

In a sea swim, the best swimmers will still ingest salt from the air. So the actual salt requirement is low. One misconception I run with swimmers into all the time, is the bodies need for potassium. How many times have you seen/heard someone have a cramp while pool swimming and someone tells them to eat a banana beforehand “for the potassium”? But usually that’s just simple dehydration. Bananas also provide magnesium, another essential salt, used for ATP synthesis, but we do not need huge amounts of either and deficiencies are rare, and in fact too much potassium in a 24 hours period will slow digestion and cause vomiting. That said, scheduling in an electrolyte is not uncommon for long swims, and allows the body a respite from the carbs.

  • Do you have a feed plan?
An hourly feed plan give a swimmer confidence their requirements are being met. Just as importantly, if the primary crew person goes down with sea-sickness, a feed plan that can be handed onto the next person means continuity in feeding. Feed plans can include extras. For example mine includes an asthma inhaler drop on four hourly breaks, just in case. The plan can also be used to schedule in special treats or prophylactic pain-killers.
  • How long do you expect the swim to last?

Do you have enough supplies if your swim runs over expected time? If you are Lisa or Stephen and are out in the water for 24 to 36 hours, do you have enough water and carb to keep going, all other things being equal? Are there enough supplies … for the crew? Better to take 40 litres and throw out 20, than take 10 litres and need 12. (I know this is not environmentally sound, but there is no way around it).

Finally, do not assume that knowledge of feeding in other endurance events will transfer to sea-swimming. It most likely will not, for example the gel packs beloved of tri-athletes, the extra salt intake and the prone position, are all complicating factors in sea-swimming.

Remember, practice everything. Which means consider and think about everything.

Feeding for long swims

I thought I’d revisit this subject, with the benefit of some few longs swims done in the past few months.

On the first six hour lake swim, I crashed (ran out of energy) on the last mile.

On the first six hour SandyCove swim this year I crashed at about four & a half hours, for twenty-five minutes, until I got some more food into me.

The next 6 hour sea went well, as have the various four and five hour sea swims.

The eight hour sea swim went fine, as did last weekend’s six hour. some more tweaking will be done for next weekend’s eight hour swim again.

The pattern we’re using is hourly food breaks. However for myself, I’ve decided I need one extra food break (at least) in a six hour swim, so after four hours I may need to move to half-hourly feeds.

I’ll use a plain isotonic mix for the first hour, moving to Maxim later on.

I had been using Hi-5 (4:1) carbohydrate to protein mix for a while but discovered at the TBBC swim that the higher sodium in it made it difficult for me to get enough in, so I changed to Maxim after that which is fine.

Depending on the day, I’ll also have some tomato or minestrone soup, with added Maxim. Using the soup alone won’t give me enough energy (that’s why I crashed on the first SandyCove six-hour, nothing extra in the soup).

I’m taking plenty of fruit also, especially in the first three or four hours. Maybe half a banana, and plenty of strawberries and blackberries, which are easy to get in quick.

Good old Kendall Mint Cake comes out at the five or six hour point. I try not to use it until the last hour or two. At that stage, I’ve reduced the fruit intake mostly. I stocked on the Mint Cake early in the year when ALDI had it on sale. I think most of the guys are converts to it also. Some of them are also using one of Finbarr’s recommendations, Fry’s Turkish Delight.

Each feed I’m getting about 400 to 500 ml of liquid in (Maxim plus soup). I have generally discarded the fresh smoothie in the sea that I was using for long pool swims, as it’s too viscous (the way I make it). I’ve removed coffee from my diet, as I mentioned before, using it only on the day of a long swim, to get the benefits. I believe one needs to be off coffee for ten days to get those benefits. I plan to hold off on it in the Channel until the last few hours.

Pre-swims of course involves plenty of carbohydrate and liquid intake. Pasta and fruit and oatmeal for me.

Endurance food and diet

Carbohydrates have been attacked due to causing sudden blood glucose spikes for the past 15 years.

However, the bottom line is endurance athletes like Open Water swimmers need carbs to function. And you don’t have to doing a 5 mile swim for this to be relevant. You need to fuel your body.

So what do we want to achieve?

Constant fuel available to be converted to glucose, to be converted to ATP, which the molecule that drives the metabolic process.

What we don’t want is to have insufficient food or run out of sources that can be converted to glucose, nor do we want sudden blood glucose spikes followed by deficits, nor insufficient glycogen stores in the body that can be converted to glucose.

When we digest, food is converted to glucose in the blood. Insulin levels rise and we use some and as insulin levels drop after we use this amount, we also store some in the liver, for later use. We also store some in the muscles for immediate demand by those muscles.

The average adult male glucogen load is about 400grams in the liver, muscles and cells, enough to fuel about 2 to 3 hours effort.

All this is a preamble to deciding what’s good and bad.

We all fall into patterns of eating and I am no paragon of diet. With all the training I do have a high caloric intake averaging 4 to 6 thousand calories a day, I’d guess, for Channel training.

Foods with a low glycemic index (GI) are better because the glucose is derived at a fairly constant rate. There’s also Glcemic Load, but let’s keep it simple.

I’ve been thinking about changing a few aspects of my diet.

Breakfast is always a freshly made fruit smoothie, about half a litre, now also always containing natural yoghurt AND a half cup of oats. This is a pretty high glucose load meal but at a mid level glycogen load, so no high glucose spikes. The addition of the oats reduces the nice taste though but is easier for me than eating bloody porridge,as mentioned previously. DON’T substitute processed oats like ReadyBrek as they are a much higher GI.
Natural yoghurt is a low GI food and a great additive. Low fat natural yoghurt is even better. (Low-fat cottage cheese is quite similar.)

Here’s one I hadn’t realised. Apples are better than bananas for fuelling. As a former cyclist, I’m addicted to the idea of bananas as a wonder fuel providing both potassium and carbs. Both are true. But an apple provides better carbsas they are lower GI. So a mix of both is better than either/or.

The biggest problem in my diet is overuse of potatoes. Potatoes are one of the very few exceptions to using fruit and vegetables as a source of good carbs. Pasta, even plain white, is a better choice, as is rice. I also tend to steam my spuds whereas baking is actually better (though I haven’t looked at the WHY of this yet). Actually making home-made chips is probably better than making mash. But it also dependent on the potato variety. Sweet potatoes however are a very good good, not at all like the ordinary potato generally used in Ireland.

White bread is essentially worse than potatoes , whole wheat bread is better than white and whole grain bread is better again. Multi-seed bagels are also a reasonable choice.

Finally a tasty alternative to porridge

Ok, this is thanks to the Hive Mind – food for breakfast, endurance sport or the Channel. I’m going to use this on our next long swim.

  • One cup of porridge oats (not pinhead)
  • 2 tablespoons each of honey and peanut butter
  • You can also add sultanas or raisins
  • Mix the peanut butter and honey to a paste
  • Add the oats and mix
  • Leave in the bowl or use greaseproof paper to make a bar
  • Place in freezer for 5 minutes (just to firm up)

It’s god-dammed delicious, even if like me you find honey too sweet. It’s also about 560 calories! Yes I guess it’s essentially a kind of flapjack. (Hopefully the dog who has been clearing my porridge bowls can lose a bit of weight now).

Evidence-based Carb loading plans- possible strategies for a marathon swim

“The No-Depletion Carbo-Loading Method

1. Perform a long workout (but not an exhaustive workout) one week before race day.
2. Eat normally (55-60% carbohydrate) until three days before a longer race.
3. Eat a high-carb diet (70%) the final three days before racing while training very lightly.

Note that you should increase your carbohydrate intake not by increasing your total caloric intake, but rather by reducing fat and protein intake in an amount that equals or slightly exceeds the amount of carbohydrate you add. Combining less training with more total calories could result in last-minute weight gain that will only slow you down.

Be aware, too, that for every gram of carbohydrate the body stores, it also stores 3 to 5 grams of water, which leads many athletes to feel bloated by the end of a three-day loading period. The water weight will be long gone by the time you finish your race, however

The Western Australia Carbo-Loading Method

1. During the pre-race week, eat normally while training lightly until the day before a longer race.
2. On the morning of the day before the race, perform a very brief, very high-intensity workout.

The creators of this innovative protocol recognized that a single, short workout performed at extremely high intensity creates a powerful demand for glycogen storage in both the slow-twitch and fast-twitch fibers of the muscles. They hypothesized that following such a workout with heavy carbohydrate intake could result in a high level of glycogen supercompensation without a lot of fuss.

In an experiment, the researchers asked athletes to perform a short-duration, high-intensity workout consisting of two and a half minutes at 130 percent of VO2max (about one-mile race pace) followed by a 30-second sprint. During the next 24 hours, the athletes consumed 12 grams of carbohydrate per kilogram of lean muscle mass. This resulted in a 90-percent increase in muscle glycogen storage.

The Western Australia carbo-loading strategy works best if preceded by a proper taper–that is, by several days of reduced training whose purpose is to render your body rested, regenerated, and race-ready. In fact, several days of reduced training combined with your normal diet will substantially increase your glycogen storage level even before the final day’s workout and carbohydrate binge.

Having said all of this, [.] note finally that carbo-loading in general has been shown to enhance race performance only when athletes consume little or no carbohydrate during the race itself. If you do use a sports drink or sports gels to fuel your race effort–as you should–prior carbo-loading probably will have no effect. But it doesn’t hurt to do it anyway, as insurance.”

Excerpted from
(There was another plan, that really wasn’t of any use for long-distance swimmers. All three did have a focus on runners. I don’t think any of this considers anything longer than marathon running event.)