Table of Contents

1.  Open Water Swimming Library

2.  Marathon Swim Training

  • Pick a Goal
  • Get in Shape
  • Endurance Training
  • Cold Water Training
  • Open Water Training

3.  Water Pollution

4.  Nutrition

(if you have something you want to submit, send it to me and I’ll post it… or if you have a question, send that to me and I’ll answer it here too)


1) Open Water Swimming Library

Here is a list of all the best books written about Marathon Swimming… because if you are, or want to be, a Marathon Swimmer there are a few must reads here!

Printable copy of:  The Swimming Library



2)  Marathon Swim Training

Okay, first of all there is far too much that could go in this section for me to write about… so I’ll just give you a very cursory idea of how I train for Marathon Swimming.

a) Pick a Goal – this usually isn’t a problem, most people want to do a Lake O Crossing or the English Channel or something.  You need to give yourself at least one year preparation… as a minimum!  Often it makes sense to pick a smaller race or swim, rather than starting with either of two of the hardest marathon swims in the world that I just mentioned!  There are lots of great solo swims and races out there, so check out the list of swims under the “LINKS” tab.

b) Get in Shape – I’ll assume you aren’t a total idiot and plan on swimming Lake Ontario or the English Channel next year and are starting from scratch.  (although you are thinking of doing a marathon swim, so it can be confusing to tell the difference between crazy and ambitious sometimes!)  You should be starting with some kind of a base level of athleticism… and a reasonable swimming background.  Although, come to think of it, that’s kind of what I did after taking 17 years off from swimming and then decided to swim the English Channel… you can see how that turned out on the video, on the “Video’s” tab and see how that turned out!  But at least I was in good marathon/Ironman shape and had been quite a high level swimmer.

The main way I would recommend “getting into shape” would be to join a Master’s swim team.  Again, check out the “Links” tab above and you will be able to find the link to numerous clubs and Masters organizations.  I’ve swum with Oakville Masters, Burlington Masters, Etobicoke Masters (not to mention LOST Masters, of course!) and would highly recommend them all.  For me it just came down to the type of training I was looking for and the workout times.  Of course it isn’t all about training, it’s also about the team comraderie, fun and motivation.  All things that I try and stress with LOST Swimming.  Marathon swimming is tough, not just the actual swim or the countless hours spent in the pool actually swimming, but staying motivated too.  So having buddies to train with for at least some of your swimming is not only nice to have, it is almost essential for those dark winter days when it is hard to drag your butt out the door!

And by the way, going out a couple of times a week with a Masters team isn’t enough.  You need to be doing 4-6 workouts per week… of high quality interval workouts.  No cutting corners.  Swim meets are a good idea too… they keep you focussed and motivated, give you something to work towards and help you monitor your progress.  I know speed isn’t important, but if your conditioning is improving then your speed should be too… it’s important to not be kidding yourself that you are working harder than you actually are!

Also, it’s never too late to get some minor stroke correction that your Master’s coach will likely be able to help you with.  That’s a whole topic in itself, but suffice it to say that the more efficient you become the faster and stronger you will be… but even more importantly for marathon swimmers is that if you have even the smallest imperfection in your stroke it will show up when you are swimming hour after hour… and will likely result in an injury that wouldn’t have shown up in a shorter swim!!!

One question I am often asked by prospective marathon swimmers is “how fast do I need to be?  I can only do 100 free in 1:45, is that fast enough?”  And I always answer “speed has almost nothing to do with it!!!”  Of course, if you are a strong and fast swimmer, that’s great… it should help you get across that much faster, but speed is only one of several important things needed to be a marathon swimmer.  Some of the important factors I think are needed to be a marathon swimmer are:

  • endurance, far beyond the norm and far more important than speed (although speed falls in the “nice to have”, not the “need to have” category)
  • open water conditioning and experience (waves, chop, feeding, night swimming, etc)
  • mental toughness, above and beyond almost any other sport (being able to handle long periods of intense pain, sensory deprivation and fear of the unknown… there are no sharks or box jellyfish in football, rugby or hockey!)
  • cold water conditioning, for most swims at least.  Either you put on fat or do a whole lot of cold water swims to acclimatize yourself to the cold… likely you do both.


c)  Endurance Training – so after you have gone from a decent base level of athletic and swimming condition near the end of summer, and then you’ve trained with a Master’s team to get into “good” shape (which is relative to the person) for 4 months or so, it’s time to start ramping up the mileage.  You should have been doing about 15 – 30 km per week of high quality swimming.  Now this is how I do it, starting at about Jan 1, or a bit earlier if you are feeling like you are in good shape… (in addition to your Masters workouts, although you might have to subsistute a long swim for a Sat or Sun workout, as long swims take priority) :

  • weekend 1 – 5k Sat, off Sun
  • weekend 2 – 5k Sat, 5k Sun
  • weekend 3 – 5k Sat, 5k Sun
  • weekend 4 – 5k Sat, 10k Sun
  • weekend 5 – off Sat, off Sun
  • weekend 6 – 5k Sat, 5k Sun
  • weekend 7 – 5k Sat, 10k Sun
  • weekend 8 – 5k Sat, 10k Sun
  • weekend 9 – off Sat, off Sun
  • weekend 10 – 5k Sat, 5k Sun
  • weekend 11 – 5k Sat, 10k Sun
  • weekend 12 – 10k Sat, 10k Sun
  • weekend 13 – off Sat, off Sun
  • weekend 14 – 5k Sat, 5k Sun
  • weekend 15 – 5k Sat, 10k Sun
  • weekend 16 – 10k Sat, 15k Sun
  • weekend 17 – off Sat, off Sun
  • weekend 18 – 5k Sat, 5k Sun
  • weekend 19 – 5k Sat, 10k Sun
  • weekend 20 – 10k Sat, 15k Sun

By the time you finish this, it should be early May… and good to get outdoors!  Let me tell you after doing all that pool work you will be dying to get back into open water!  As I always say “pool swimming is to open water swimming what treadmill running is to trail running!”… no comparison.  And once you’ve gotten used to it you’ll love it!

Once you are comfortable with how long it takes you to swim 5k or 10k, don’t count lengths!!!  Just swim the time, it really doesn’t matter if you are out by a length or two… you have to get that timing and length counting mentality out of your head… and learn to switch your brain off and just go.  Being able to do this is a real skill and has to be learned.  But once you have it makes all the difference in the world, it takes a long swim from boring to… medatative.

Other things to keep in mind:

  • these long swims are in addition to your Masters workouts
  • this is for a major marathon swim, like the English Channel or Lake Ontario, if you are doing the 20k Swim Around Key West for example, your training might not be quite as intense.
  • you might have to play with the distances, but you get the idea… it’s tough.  And if it doesn’t scare you a bit then you have never done training like that or you are kidding yourself!
  • keep a log book!!!  This is a must.  Period.  Keep track of your distances, nutrition while swimming, how you felt, your weight, water temp, race times, anything remotely relevant.  I’ve got an excel based log book I’ve kept since 2003 for swim, bike, run & dryland (yoga, weights, etc), it graphs it and totals it and all kinds of things.  Not only is it interesting to see how fast I used to be but it helps with training and learning from all my mistakes!  (if you want to use mine, let me know and I’m happy to email a copy to you!)
  • train for the worst and hope for the best!

Now you are in good shape, you have some significant endurance… and you are ready to start your cold water and open water training!

Below is a article by Scott Zornig, President of the Santa Barbara Channel Swimming Association, on endurance training for marathon swimming.

Training for a marathon swim

If you are new to our sport, you may have received an abundance of advice on how to train for a marathon swim. It was likely all good information, but it also may have been all over the place which can be confusing. Training for a marathon swims is very personal and usually involves balancing job and family. Most will agree on one thing, which is you need to put in a lot of yardage for your best chance of success.

Four of SBCSA’s board members agreed to share their yardage, by month, done in years when training for a marathon swim. Although this study is far from scientific, it might provide ideas on how to structure your training programs.

# of Marathon

Month    Ave. Yards    % of Annual Yards     Swims by Month

  • Jan            77,322                 7.9                   0
  • Feb          111,849                11.5                  0
  • Mar            77,810                 8.0                   1
  • Apr            81,249                 8.3                   1
  • May           93,863                 9.6                    0
  • June         103,621               10.6                   2
  • July          100,216               10.3                   4
  • Aug            98,577               10.1                   6
  • Sept           68,535                7.0                    6
  • Oct            60,288                6.2                    3
  • Nov            51,600                5.3                    0
  • Dec            49,895                5.1                    0
  • Total       974,825             99.9                   23
  • The average number of annual yards amongst the four marathon swimmers during marathon years is 974,825.
  • Yardage generally builds until June and then declines from there (Note: February includes fitness challenge yardage resulting in an aberration).
  • February, June and July were the months with the highest yards.
  • October, November and December were the months with the lowest yardage.
  • The group of four has done a total of 23 marathon swims in their careers for an average of 5.75 each.
  • The two most popular months for marathon swims were August and September with 6 each, followed by July with 4 and October with 3.
  • The earliest swim was done on March 8th and the latest swim was completed October 10th.


d)  Cold Water Training

This is all about walking that fine line between cold water acclimatization and hypothermia.  And it’s tough.

Here is a response I wrote to a new marathon swimmer about hypothermia that explains much of it:

With regards to your email about being concerned about losing feeling/control of your fingers… it’s called “the claw!”

Yes, it is common, any marathon swimmer worth his salt has had it… your body is just pulling in all the warm blood from your extremities, your fingers and toes initially, to keep your core warm… which is the early stages of hypothermia… but really no big deal. The thing about hypothermia is that people often freak out because they hear that you were hypothermic or it scares you a bit because you are physically going through something you have never gone through before.

But, a couple of things about hypothermia… first of all, hypothermia is on a sliding scale, it is all about the degree of hypothermia. By definition it is “the lowering of the body core temperature”, which leaves it pretty wide open. It can be anything from shivering at the bus stop… to convulsions, seizures, unconsciousness, pulmonary edema and eventually death, but usually somewhere in between.

I’ve been to the seizures, unconsciousness, pulmonary edema level twice (boating accident in grade 12 and the English Channel in 2006, when they pulled me out unconscious)… and rest assured that “the claw” is a lot closer to waiting at the bus stop than it is to being pulled out unconscious.

This isn’t to say to treat it lightly, it is still very important to know the stages and what stage you are at while you are swimming. I remember having a seizure in the leaky canoe in grade 12 telling my buddy what stage I’m at… and that the next stage is death… fortunately we were rescued shortly after that. It is all about experience, so now you know that having the claw isn’t a big deal… it is still uncomfortable as hell, but not dangerous… but you have to be constantly monitoring your own body to see if you are maintaining, warming up, or getting colder… and therefore showing more signs. A good indicator of being “too cold” is shivering even while you are swimming… then it’s time to get out. I remember swimming the EC and my feeds would last about 10 – 15 seconds and I would start shivering hard, the second I stopped to feed, but was okay once I started moving again… very close to that line for numerous hours… of course, I eventually went over it and don’t even have any recollection of the last 1 1/2 hours, but I was willing to push it on that day, and I had a very experienced crew that was aware of my condition and progression.

It is also important to tell your crew that you have the claw, etc. so they can monitor you as well, and pull you if need be. It’s especially important to tell your crew because one of the signs of severe hypothermia is that you become stupid… ie. less lucid… you can’t answer the simple questions that your crew asks you when testing you for hypothermia (ie. not what your name is, because it is too easy… but what was the score in the hockey game last night, for example, because it is something that you actually have to think about it, not questions that you have memorized).

The second this about hypothermia is that it’s easy to treat.  It’s not like you were biten by a shark or are drowning… you just need to warm up.  Often you are fine when you get out of the water and 10 – 15 minutes later you really start shaking… and it can last for as long as a couple of hours.  This is because all that cold blood that was out in your hands and feet is now returning to your core… and your are getting “after-drop”.  That is, your body core may drop even further than it was when you were cold.  The cure to hypothermia is simple, warm up as best you can.  Warm liquids is best… lots of clothes… hugs (ie someone else’s body warmth)… get out of your wet clothes… but stay in your wetsuit if it is warmer.  If you are able to, go for a short run.

The thing is, you want to always be pushing your cold tolerance, which is what makes you more acclimatized and able to handle the cold for a longer period. Just be smart about it and if you know it’s cold and you are going to try and push your limit on that particular day, do it with a crew or when you are close to shore with friends, etc.


Core Temperature

Celcius         Ferinheight

37.0                  98.6                  Normal body temperature

Mild Hypothermia

36.9-36.1        98.4-97.0        Goose bumps; sporadic shivering

35.5                  96.0                  Uncontrollable shivering

35.0                  95.0                  Voluntary tolerance limit; deep cold; numbing; blue  skin               

Moderate Hypothermia

34.9-34.3        94.9-94.0        Mental confusion begins; motor performance impaired: speech slurred, loss of coordination, “claw hand”, other muscle stiffness; skin may be grey

32.8                  91.0                  Severe mental confusion; grossly impaired motor performance; shivering impaired

Severe Hypothermia

32.2-31.1        90.0-88.0        Heart rhythm irregularities; severe disorientation, hallucinations; rapid deterioration in motor performance: drop in stroke rate, hip drop or directional instability; dilated pupils; grey-white skin; shivering stops

31.0-30.0        88.0-86.0        Loss of consciousness; no response to pain

28.0                  82.4                  Ventricular arrhythmia

26.6                  80.0                  Death

 * It is recommended that a swim be terminated if the swimmer definitely has moderate hypothermia or the swimmer has the beginning of moderate hypothermia and any of these risk factors.

Always good to read up on these things too!


e)  Open Water Training – this happens at the same time as your cold water training and continues as the water warms up.  There are specific techniques that can help you with all the issues in open water swimming, but the best way to learn is to do!  Get some experience.  And it is important to note that if you are swimming across Lake Ontario or the English Channel, doing your open water swimming in a rowing basin or a small quarry is of very little value.  You need to get out in the big water and be tossed around a bit.  These are the things you need to practice and learn how to deal with:

  • waves (not necessarily bad, especially if they have a nice long wave-length)
  • chop (much different and tougher than waves)
  • cold (there’s a whole section on that)
  • jetsam and flotsam (from sea weed, to logs, to dead giraffe’s, yes, in the Manhattan Island Marathon Swim one fell in from the Bronx Zoo!)
  • salt water (depending on the swim)
  • night swimming (learning to deal with the aquatic boogie-monster)
  • nutrition (what to eat)
  • feeding (how to eat)
  • peeing (hey, this is really important, believe it or not!)
  • sea-sickness (not just for the boat crew!)

There is one other section that I haven’t touched on, because it changes with each race, but it is also very important… the logistics!  Money, flights, accomodation, timing, crew, equipment, etc… oh, and did I say money!

So that’s the short answer as to how to become a marathon swimmer!  Obviously things change from person to person and from swim to swim, but that’s a good starting place… pick a goal… get in shape… add some distance… acclimatize to cold water… learn open water swimming… then go do it!  And learn from your mistakes for your next big one!

And you know what… even though this whole section should have scared you a bit… don’t be overwhelmed, it’s tough but do-able… and most importantly, it’s worth it!!!


3) Pollution

E. coli levels can be an issue in any body of water and that is true for Lake O as well.  E. coli is the most common pollutant to cause a body of water to be closed to swimming.  Escherichia coli is a common bacteria that naturally occurs in warm blooded animals, but certain strains may cause a type of food poisoning.

If it seems like you hear more about it in Lake O, it is because it is not tested by the government in most smaller lakes, and therefore not reported by the media!  (although that is changing and more smaller lakes are being tested and results being posted on government websites as well).

Generally speaking the E. coli issues in Lake O are over-blown. There are spots in the lake that can get E. coli levels that are too high to swim in safely, Cherry Beach is one that often has that problem, for example.

I have found that the press sometimes makes gross generalizations, like “Lake O is closed for swimming” or is “unsafe for swimming”… without qualifying the statement or it is buried in the 22nd paragraph.   However, given that it is the 11th largest lake in the world, that statement is virtually impossible!  Some areas may have levels that are too high, but that is not at all true for the vast majority of the lake.  And that’s how the myth gets started and exaggerated to include the whole lake.

The factors that contribute to high E. coli levels are: water temp, circulation, water depth, wildlife, sewers.

So an area that is nice and warm (good for swimming in most people’s mind) and likely shallow if it is warm, and is in a protected bay or by a breakwater, and doesn’t circulate well… is far more likely to have E. coli issues.  Also lots of ducks and geese can add significantly to the problem. Run off after a heavy rain can increase the problem if you are swimming near a sewer outlet too.

For LOST Swimming, we swim in Oakville which, fortunately is a great place to swim.  I’d love to say I planned it that way, but it was more just luck… mind you, I probably wouldn’t have been swimming there in the first place if it was polluted!

Anyway, where we swim is pretty much the deepest part of the lake, which means it is cold (which is good in this case… makes for cold swimming, but good in preventing E. coli pollution), it is on a straight shoreline rather than a bay, which is also better for circulation.  Also there is no sewer outlet where we swim and for whatever reason, there aren’t enough enough ducks or geese in the area to cause a problem either.

The long and short of it is that in several years of swimming here, no one has had so much as an ear infection (which can’t be said for Gulliver’s Lake or Kelso, although they are okay early in the season)… so, yes, it is a great place to swim!



4) Nutrition

This is key.  Period.

As any Ironman will tell you, nutrition is the 4th discipline… swim, bike, run, eat.  Because it is as important as any of the other three disciplines in determining if, or when, you finish the event.  There isn’t an experienced Ironman out there that hasn’t screwed up their nutrition… and had to pay the price.  Paying the price usually involves some combination of: bonking, vomiting, diarrhea, dehydration, over-hydration, feinting… and probably a few other things that can make you feel like crap and either slow you down or stop you in your tracks.

So let’s look at what goes wrong and why and then we’ll look at what to do to make things go right.

  • bonking – this isn’t just some euphemism for getting really tired… it is an actual term used to describes a condition caused by the depletion of glycogen stores in the liver and muscles, which manifests itself by sudden fatigue and loss of energy.  The term “bonking” comes from marathon running, when you “hit the wall” or bonk into the wall.  The term is often wrongly used to describe someone who is out of shape and simply couldn’t go any further.  The good news, like much to do with nutrition, is that it is usually relatively easy to fix and prevent.  If you feel yourself bonking, well it’s pretty much to late to still make your Boston Qualifying time, but if you are in an Ironman or a marathon swim, you may still be able to recover.  The answer: slow down or stop, ingest some food and/or drink, particularly something with high carb content… and the easier to digest the better.  The easiest is liquid (such as Carbo-pro or Maxim), then gels (Power Gels or any other kind of gel, my favorite is Carboom, it tastes more like jam than toothpaste!), then solid (which is just about anything you can get down).  The problem is that this is sometimes easier said than done.  You usually don’t know you are there… until it is too late.  Which is why you need a plan… and need to stick to the plan… and need to adjust the plan when the plan isn’t working… which again is easier said than done.
  • gross stuff (like vomiting, diarrhea, peeing, feinting, dizziness) – so this is the type of stuff that isn’t spoken of in good company… so I’ll talk about it here! … (more to come)