Tag Archives: endurance

Limiting Factors in Marathon Swimming – Part 3 – Psychological Factors

The previous two posts dealt with the physiological and environmental limiting factors of marathon swimming. As noted in Part One, non-swimmers and those unfamiliar with the sport tend to see the physiological factors as the greatest hurdles for swimming further distance, often imagining that marathon swimmer’s have some physical capability beyond the average person whereas the Environmental Factors in Part Two are possibly more likely to be a governing factor.

Assuming a swimmer has done the training, for unsuccessful swims the environmental factors are more likely to cause a swim to either not start at all or to be abandoned, and of those weather will always be the swimmer’s greatest challenge.

Experienced swimmers however will generally mostly agree that marathons swims are “more mental than physical”. And because of the complexity of individual psychology, these factors are not as easily codified or itemized, and what I may consider the greater challenges may be not such an important item for someone else, but some can be identified.


Alan Clack at Varne, waiting for the word and the weather
Alan Clack at Varne, waiting for the word and the weather

Of all the aspects of marathon swimming that I feel are most misunderstood, this aspect may be the least appreciated. It is very difficult to explain the psychological pressure endured by a swimmer who is waiting for a weather window to open. The swimmer may have invested two years of their life and a not-insignificant amount of money, only to find they don’t even know if they will swim. Depending on the person this can lead to stress and lost sleep. While this occurs prior to the swim, assuming there is a wait period, it’s impossible though to know if or how many swims may have been unsuccessful because of the pre-swim stress affecting the actual swim.

Other swimmers, having waited a lifetime for an English Channel solo in particular, can make poor last-minute decisions or changes regarding crew or feeding. Others feel that having waited those years, they must take chances. Probably the most likely impact of waiting is the decision to swim in a marginal weather opportunity that they would otherwise not have swum in. It is very easy to say this from the outside, much much less so from inside the bubble of the waiting swimmer in a marginal situation, when the pilot isn’t giving a clear indication and the decision rests with the swimmer.

Uncertain duration

Almost all swimmers step into the water with some target time or duration in mind, even if it never articulated to anyone else. Some of us learn this error the hard way and spend the rest of our swimming lives repeating it. All that counts is standing up in France is my own oft-repeated variation. A number of swimmers have found that their swim due to be two or six hours longer than expected, they have no desire to continue.  (You might recall this was the subject of a question I asked Harley Connolly, Trent Grimsey’s coach, prior to his English Channel record attempt, whether he would continue if he wasn’t on record target). Imagine this extra time extrapolated to a two-way Channel swim or a Cuba to Florida swim, when the estimated time is subject to even greater deviation. Imagine you are expecting to be swimming for 40 hours (40 hours!) and then you are told “no, it’ll be 54 hours“, longer than anyone else has ever swim? That would bring a unique psychological weight. But all additional swim time brings the possibility of being too much for a particular swimmer.

Unprepared for or unexpected events

Many marathon swimmers will go through personal form of visualisation to help ensure a successful swim. Maybe imagining picking up a rock on Vista Point or Cap Griz Nez or returning home successful. Visualisation is a powerful and well-known tool for athletes (and others). For swimmers this visualisation can include the various things than go awry during a swim, such as worsening weather or digestion or elimination issues. But what happens when reality sidesteps your visualised possibilities? Swimmers expecting a usual night-time start who instead find they have a mid-morning start and therefore will be swimming into the night instead of into the day? It is a more difficult thing to have night after ten hours of swimming than to have dawn after six hours. One is a prolonged boost, the other can act as a mental hurdle or even cliff.

Steve Munatones regularly repeats that the most important rule of open water swimming is to expect the unexpected. But while that’s correct and reasonable, it’s also easier said than done when the nature of unexpected events is to blind-side us. Some can be dealt with and the better the training and the more the experience the more likely the swimmer is to have to run into various scenarios. The epitome of this type of preparation surely has to Lisa Cummins whose training included every possible variation she could manage, from deep cold to night swims, to various feeding methods to the Torture swim, this type of training common to Sandycove Island Swim Club Channel Aspirants. All are intended to give the swimmer the broadest possible well of experience from which to draw. But there is always something unexpected out there for every swimmer. How can you prepare for solid fog? How can you prepare for getting trapped under the pilot-boat?


It can be said that the question the endurance athlete dislikes the most is Why do you do it? We all have our own particular reasons for swimming, every swimmer’s motivation is a unique recipe which includes some obvious ingredients such as proving something to themselves, looking for limits, fighting the inevitable onslaught of age, or simply loving open water swimming. To these will be others particular to the individual, such as seeking approval, validation, remembrance of someone, or overcoming some physical hindrance or others.

Whatever the unique blend of the swimmer’s psyche they may find that in the heat of battle, those reasons evaporate or are not sufficient or may have been misdirected. This isn’t a criticism, it doesn’t mean those swimmers are missing something. Instead for some swimmers it is in the swim that they discover something about themselves or their motivation which means that finishing a swim is no longer necessary to meet those internal expectations or reasons or that the training or the swim itself regardless of outcome was the real reward. Whichever is the case only the swimmer themselves knows the internal landscape and the rewards and losses and costs of the effort, successful or otherwise.

Self doubt

Made of water
Made of Water

Or should it be self-belief? How I title this section is surely more a reflection of my own mental landscape than any definite assertion. If you read about any adventures sports or know or follow any adventure or top class sports people like Adventurer Dan Martin, Ocean’s Seven swimmer Stephen Redmond, International elite swimmer Chris Bryan or adventurer Lewis Pugh or many others on Twitter, something you’ll notice amongst many (but not all) of them is that they post inspirational quotations. Some come from themselves, some are quotations that come from others that they have found useful or that they appreciate and wish to use to inspire others. In a way these quotations act like a shorthand for the internal mental effort required.

Part of the nature of the human condition is self-doubt and it is one of the most limiting factors of all. After all without wishing to start repeating a lot of those inspirational quotations, the person who believes they can, and the person who believes they can’t are both right. If I quote that, it doesn’t mean that I absolutely follow it. Personally the problem I have with inspirational quotations is that they make me feel inadequate, with all their exhortation of overcoming and victory. Life seems to me at best a series of compromises.

Nonetheless a certain amount of self-belief is required for big swims, or anything else. You need the belief that you can keep turning the arms over for the next ten minutes, feed interval, hour, tide, night or day. Some of that comes from training or experience, some of it comes from knowing yourself. Some of it we learn along the way. But we can also run out of it and run up against limits. Almost all of us have some limit to it.

Despite that, I have my own favourites. This Socrates quotation from a long time ago remains a favourite. During Channel training my training log said “Today is the Channel” so I would remind myself of the journey every day. Another is simply; “I do not stop when I am tired. I stop when I am done“. Even if I don’t always believe it, or myself…

This is another of the private internal battles the swimmer must undergo. The biggest difference between the same person who stepped off the beach in England, and who swam ashore in France, is the increase in self-belief, what we usually term confidence.

An extract from Channel Swimmer David Walliams' Channel mental training preparation
An extract from Channel Swimmer David Walliams’  mental training preparation

There are of course the other more mundane psychological aspects of a marathon swimmer’s life: Boredom, worrying about imminent physical problems, regretting missed training, anxiety about water depth or creatures, or ever embarrassment about bodily elimination, these are the ongoing easier understood issues of a marathon swim. But no less important for being more mundane or easier to convey.

Channels swimmers often say it is 10% physical and 90% mental. I prefer to think that it is 90% physical. And 90% mental.

Unlike most of the items in Parts One and Two, these aspects are neither visible, nor particular to marathons swimmers. And yet they can be bigger hurdles for being invisible and private and general.

But the biggest hurdle isn’t necessarily one or the other, but the one that either stops you or took the most to overcome.

Next time you look at any endurance athlete or event and in particular marathon swimmers, I hope I’ve given you some idea of the Limiting Factors with which each and every one must necessarily deal.

Limiting Factors in Marathon Swimming – Part 2 – Environmental Factors

In Part One I covered the physiological limiting factors in marathon swimming.

The various environmental aspects of a swim are not insignificant. They are especially important in that they all lay outside the swimmer’s control and often even outside the control of the support crew.

Water Temperature


This is generally a known factor prior to a swim. Swims are either cool or cold water like the English and North Channels or warm water swims like Maui, Rottnest, Manhattan or Chloe Maccardels’ upcoming Cuba to Florida attempt. A few fall into an intermediate category defined more by the swimmer’s experience, such as the Catalina and Gibraltar Channels. Sudden changes in temperature are rare in marathon swimming and where they are possible they are also understood; such as South Africa’s west coast which is prone to sudden wide water temperature changes, and the California coast where the sudden transition from very deep water to a shallower continental shelf very close to the  mainland can cause cold water upwelling at the end of a marathon swim. Air temperature is obviously much more variable and a condition of the weather but extremes of air temperature are not usual during a swim. A five degree Celsius differential can be significant for a swimmer if such a drop is also accompanied with a breeze or wind which can sap the swimmer of body heat.


Lion's Mane jellyfish
Lion’s Mane jellyfish

The recent and future attempts at a distance and time records by necessity are held in warmer waters such as Cuba to Florida.  These water are home to jellyfish with debilitating stings such as Box Jellyfish. While the cold waters  of the North and English Channels are home to Lion’s Mane and Portuguese Man O’War’s endurance records are less likely and jellyfish stings in the English Channel are rarely more than intermittent, though the North Channel (the Mouth of Hell) can have miles of Lion’s Mane blooms, part of what makes it the ultimate channel swim. Attempts to swim in these waters divide swimmers in two ways: whether attempts should be made in locations not considered possible without additional protection or exceptions to the usual rules, and if so are jellyfish protection suits acceptable or the thin edge of a wedge that will inevitably lead to more overt (or hidden) performance enhancing suits? (See Evan’s analysis of his survey of marathon swimmers for an excellent overview of the contradictions of divisions and unity in the community).


The Man In The Grey Suit is a subject of great concern (and discussion) for distance swimmers. Not of any real concern here in the north-eastern Atlantic, they are a greater hazard in the warmer waters elsewhere, particularly California, the Caribbean, Hawaii, South Africa and Australia. The Cook Strait Channel swim in New Zealand is unique in having a shark evacuation rule. Shark cages have been used for marathon swims in the Caribbean and South Africa at least. Shark cages are however considered swim assistance as they increase the swimmer’s speed through eddy current drag. Other possible control methods include electronic shark repellents (whose effectiveness is not entirely assured or quantified), armed boat crew or armed or otherwise scuba diver outriders.


These are amongst  the most variable of environmental factors and therefore potentially also the most limiting. Because swimmers move slowly relative to even a sailing boat, we are vulnerable to slight deviations, miscalculations or just insufficient data, the most likely cause. Even in such a well-travelled and mapped location as the English Channel, especially for swimming, pilots will occasionally speak of tides arriving early or late or with a difference force than expected. Tidal currents are understood at a larger scale, hundred of years of navigation have mapped the seas for craft, not for swimmers. Tides act in a similar chaotic way to a weather system, which means that small deviations will always creep in. The only way to improve accuracy of prediction is to improve the data, and this is not practically possible or even desired for small tidal variations. As swims occur in less well-known or new locations, the likelihood of discovering unknown local variations outside marine charts increases. Half a knot current, barely detectable to a boat, is enough to deviate a swim over hours from a projected or necessary course.

Global tides
Global tides

Crew and boat

Any English Channel pilot will confirm that one of the most likely causes of unsuccessful Channel swims is poor selection of support crew. The most likely cause is mal-du-mer, seasickness. For some people seasickness is a completely debilitating ailment that can sap all willpower and strength and there is no way to know whom it will strike. The solution of course is to have experienced crew. Even this can fail because people experienced on powered craft will be at the mercy of the choppy water amplified on an almost stationary craft. Other crew issues can also arise, whether accidents or other illness. Anyone who hasn’t been on a rocking boat looking down on a swimmer is unlikely to understand! And not unknown are mechanical problems on the pilot-boat. Most pilots are by necessity practical mechanics able to address problems as they arise, but not all problems can be fixed with a wrench and hammer while rocking about on the sea.

Channel boat The Viking Princess
Channel boat The Viking Princess out of the water


Weather changes are the bane of English and North Channel swimmers particularly. Other Channels like Tsugaru and Gibraltar and Cook are also subject to constantly variable and unpredictable weather patterns. If you are used to the predictable weather of the west US coast, with morning offshore and afternoon onshore breezes, knowing your swim will almost certainly take place with a 48 window, the difficulty of allocating two weeks or even long (like the North Channel) and still being completely unsure of getting in the water is shocking. Weather constraints obviously ran the full gamut. In the North, English and Gibraltar channels the main concern is wind (and its effect on the seas). Fog can also be a problem with 2012′s Channel season infamously seeing three solos on one day abandoned within a kilometre of France for the first time in 137 years. I’ve warned previously that fog may be the most dangerous weather condition for swimmers. In warmer humid climes like Round Manhattan, and the Caribbean, lightning storms are a serious cause for worry, a swimmer or boat caught exposed out on the water is in real danger. Having to wait for or even postpone a swim is something many marathon swimmers have undergone and the mental pressure this brings is often not inconsiderable, which I will discuss further in the next and final part.

Coming in part three, Psychological Factors.


Use of choline supplementation in marathon swims (or ultra-endurance events)

I don’t like dietary supplements. B Complex, multivitamins etc. The little reading I’ve done so far on the subject indicates little or no benefit is gained from commercial multivitamins for endurance athletes But I don’t rule it out…

Since my EC, (too late that is), I’ve had a few interesting conversations with an online friend and endurance athlete (hey Herman!), who has a background in nutrition, who has convinced me to look at some specifics. When I’ve talked to others in this line, they don’t have any experience with real endurance events, much more in strength events, track or field or team events. But given his own endurance exploits Herman has given this more thought than those advising other athletes. Also, having done a Solo, I am interested in how we can do it better and the scientific improvements we can bring to our almost non-studied pursuit. Evan Morrison has started a series on this subject also, which prompted this post, as so much Evan writes so often does.

So, what can we do better?

Amongst the things that Herman suggested we increase was Choline. I’ll address the others separately, (why write one post when I can write two?).

So what is Choline, and why increase it?

To the Research-mobile Batman!

(There’s three links there, for the hypertext inadequate).

Mihai Niculescu

Choline is a dietary and nutritional Requirement, like vitamins. It’s often grouped together with B-complex vitamins. It’s required for a variety of purposes including supporting cell structure and integrity, muscular control and neuro-transmission (signalling between neurons). So just thinking from a heavy training point of view, and the precision that swimming normally requires combined with heavy training loads, these seem quite apposite.

The body has a good supply of choline, and retains it well into endurance events but can drop precipitously. Studies at the Boston Marathon in the 80′s show runners could drop 50% over the curse of a marathon. So what about a 5 to 40 hour swimming event?

WE DON’T KNOW! On an initial search I can’t find (unsurprisingly) any studies on choline in ultra-endurance events.

Oh, and apparently, low choline can lead to an unpleasant (fishy) body odour, which no amount of washing will remove. I’m not sure how you segregate this from open water (sea) swimmers who just smell of fish anyway! :-) Which is no worse than the six months of pool training when you smell of chlorine.

Like ALL essential nutrients we can get everything we need from our diet. But the primary forms of choline and changes to a modern diet both mean we could be operating on low choline levels.

The Adequate Intake (AI) of choline is 425 mg (milligrams) per day for adult women; higher for pregnant and breastfeeding women. The AI for adult men is 550 mg/day.

There’s a study that shows AI, Adequate Intake, may not actually be adequate.

Here’s a table straight from Wikipedia:

Animal and plant foods Choline (mg) Calories
5 ounces (142 g) raw beef liver 473 192
Large hardboiled egg 113 78
Half a pound (227 g) cod fish 190 238
Half a pound of chicken 149 270
Quart of milk, 1% fat 173 410
A tablespoon (8 g) soy lecithin 250  approx. 60
A pound (454 grams) of cauliflower 177 104
A pound of spinach 113 154
A cup of wheat germ 202 432
Two cups (0.47 liters) firm tofu 142 353
Two cups of cooked kidney beans 108 450
A cup of uncooked quinoa 119 626
A cup of uncooked amaranth 135 716
A grapefruit 19 103
3 cups (710 cc) cooked brown rice 54 649
A cup (146 g) of peanuts 77 828
A cup (143 g) of almonds 74 822

So you can see why it would be easy to not get enough. I like liver, but I don’t eat beef liver, (which is horrible and better fed to dogs) and half a kilo of liver a day of any kind would lead to vitaminosis, which is pretty dangerous, and why I limit liver intake when training hard to once a week.

Maybe you really do eat a kilo and a half of cauliflower a day, more power to you if so, but I pity the people living with your colon.

Or just a daily, and probably quite odd mix of these items. Maybe a cauliflower, milk, quinoa, spinach and fish smoothie? Yum.

But modern diet has had us reduce red meat and eggs for other reasons, concerns over cholesterol, etc. Milk is a good source (human milk is very high in choline, for infant development) and probably the easiest to take, something I drink plenty of to support training. I’m wasn’t sure what the hell a quart of milk was, apparently it’s almost a litre. America, please see above cartoon. Again.

Choline is beneficially linked to foetal development, cardiovascular system, and anxiety reduction (not depression), increased IQ in infants, possibly lowered cholesterol (contradicting studies), and mental acuity and memory in mice, and diets with no choline can lead to liver or muscle damage in 80% of cases. On the negative side, there’s a study that it can lead to colonic polyps in women. Or increased risk of diarrhoea or flatulence. One study shows that endurance athletes can be deficient in choline, which is the real point.

Lacking this intake of, it seems choline is possibly a good recommendation for diet supplement in endurance athletes. It is assumed to come in diet from Lecithin, which is how strength athletes (always keen to shove pills into themselves) often supplement. It’s European E-number E322, derived from soy or egg yolk and it’s used as an emulsifier (stabiliser) in processed food, such as some margarine, baking or processed chocolate bars (not high cocoa percentage chocolate bars). But (older) studies show lecithin isn’t effective in choline supplementation, that maybe only 4% of lecithin is actually converted to choline.

Yes … but. The but is ask what we can do. Without studies of deficiencies, supplementation and effects for ultra events, we simply don’t know.

Extracting from one article:

Evidence for choline supplements
But can choline supplements really be beneficial? We know for sure that choline levels do plunge near the end of a marathon, and we also know that choline supplements can prevent this devastating downswing. In one study, the simple act of taking in two grams of choline before exercise began totally prevented the fall in choline normally associated with prolonged activity.

However, the simple maintenance of choline levels does not automatically mean that performance will be enhanced. To check on the performance part of the equation, researchers recently asked 10 trained runners (eight males and two females) to run 20 miles as fast as possible after taking 2.8 grams of choline citrate one hour before the run and the same amount (adding up to 5.6 total grams of choline) at the half-way (10-mile) point of their efforts. On a second occasion, the athletes ran the same distance without taking choline. Seven of the 10 subjects ran better times after taking choline, and average time for the 20-miler was five minutes faster when choline was utilised (2:33 versus 2:38).

The researchers were also able to show that plasma choline levels decreased significantly after the placebo (non-choline- supplemented) run but actually increased by 74 per cent at the end of the 20-mile exertion when choline was taken before and half-way through the run.

Cavet: Those are only two small-scale studies, in different conditions (because we always have to remember a few things: Cold & Salt water ingestion as environmental factors for us).

There are two counter studies also. A study of moderate distance cyclists (150 kilometres per week) training at less than VO2 Max displayed NO improvement from choline supplementation. But there is a suggestion in an analysis of one study that choline supplementation is only effective OVER two hours of exercise. Whereas in the other, blood choline was raised, but performance wasn’t.

There IS a small study on pool swimmers, who were using results from an Interval T-30  (thirty minute time test for distance) as the measurement. 11 out of 16 showed an improvement.

Okay, so we’re not left with a lot of conclusive evidence. But there does seem to be a leaning toward choline as being beneficial for ultra-endurance events.


In the meantime, it’s not a regular supplement, I don’t significant use in boosting it daily, but that would depend, as above, on your diet. Eat more eggs, you need less choline supplementation. If it is of any use to us, it’s directly prior to and during the events themselves. I see if I can influence any of next year’s Aspirants to try it out. In the meantime I don’t like keeping these thoughts to myself, our community is based on friendship and sharing knowledge. So here it is for your consideration. And any useful information anyone could add would be great.

Lastly, the actual supplementation. Well it’s not something you find in pill form on the supermarket or pharmacy shelf. Apparently some electrolytes has choline as an addition. The best uptake form is either of the choline salts, choline chloride or choline bitartrate, which are absorbed really quickly into the blood, within 30 minutes. If taking it, you take about 2.0 to 2.5 grams before the event, and after 2 hours, (about 0.2 gr per kg of body weight). For a multi-hour ultra event, I would GUESS, that taking it subsequently every two to three hours would be best. If it is of any benefit.

References from:

Wikipedia, PubMeD, Cochrane, American Journal of Clinical Nutrition, Peak Performance Sporting Excellence, new England journal of medicine, Google Scholar

Endurance Recovery

Part of the design of Eilís’ training regime was to enable quicker post-Channel recovery.

Given the extra work I had to do during the swim, the six hours extra duration over what I was expecting, I wasn’t sure how long before I felt recovered. Jen was definitely back before me.

I was also injured afterwards. And tired for at least three weeks. I would generally feel fine, but when I tried anything remotely strenuous, the tank was empty.

But the shoulder is now about 90% recovered, and only sore while swimming, and not very sore at that. Last week I got to the point where I wanted to swim,so I went back to the pool. And with easy days of only an hour, it’s enjoyable in a way it wasn’t back during much of the Channel training regime. My speed is even more mediocre. My aerobic capacity is not what it was not so long ago.

But I am recovered, I think. At least I won’t embarrass myself at Sandycove too much next Saturday. Eilís’ training proves itself again.

There’s an endurance sport adage that I came across in an old running book. For an endurance event you can do approximately two and half times your longest training event.

However, if you want to do it regularly OR want to recover well, then you must train longer.