Too Much Water? Not Enough Salt? Hyponatremia in Marathon Runners

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Hyponatremia (low sodium, or “water intoxication”) is a risk for runners with atrial fibrillation. It is certainly a risk for me and I believe I have experienced it a number of times in the past. Personally, I am much bigger than most marathoners (6’3” 205 lbs), and because of that and the atrial fibrillation, much slower – so I’m out there twice as long and sweating twice as much. Plus – over the years it has been drilled into all of us to make sure we drink enough water.

Ironman athletes, ultrarunners, and bigger runners are all at increased risk because we are simply out there for much longer periods of time. Women athletes tend to be at higher risk for hyponatremia – it has been found that women hydrate more during a race.

Drinking enough water is a good idea – but it needs to be accompanied by increasing salt intake.

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Normal levels of sodium are about 135-145 mEq/L. Symptoms are likely to begin at 130 or lower and if you get below 120 the condition may become fatal. While there are a number of medical causes for hyponatremia marathon runners fall into the category of consuming too much water and not enough sodium, and sweating out valuable sodium. Think of the white dried salt on your temple or on your hydration pack straps after a long run.

Symptoms include bloating, headache, swelling (check to see if your ring or wristwatch seems to be getting tight), nausea, vomiting and eventually weakness, restlessness, confusion, and well . . . it just gets worse from there. It is particularly problematic for runners because some of the symptoms (headache, nausea, cramps, and dizziness) are the same symptoms for dehydration so the impulse is to drink more water – which of course makes it worse.

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There is currently an ongoing study at the Houston Marathon involving volunteers who are followed closely, weighed, fluid intake measured, lab studies obtained, etc. The study found that runners with lowered sodium levels drank more water, retained more water than normal volunteers, and they lost more total sodium and had saltier sweat.

Runners who were dehydrated but not hyponatremic had higher heart and respiratory rates, felt worse, and had lower blood pressure than hyponatremic runners. The hyponatremic runners felt better, but had more nausea and bloating.

What can be done?

Drinking less water is sometimes recommended but it is difficult to do when you are used to drinking a lot of water while running. I’ve tried drinking less water during a marathon and frankly I think it made things worse. Also some runners can become hyponatremic without over-doing the water consumption.

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Weighing yourself frequently along the course and looking for weight gain (water retention) has been recommended – YEAH RIGHT! How is this going to happen?

Personally I try to drink water with sodium supplemented (NUUN, GU Brew), and try grabbing some little pretzels at aid stations (if available); but some research suggests this might not always be helpful.

“Watch out for feelings of confusion, nausea, fatigue, and particularly vomiting and swollen hands and feet. If you experience these, seek medical help.”

Fatigue? Really? Fatigue during a marathon – you don’t say? Isn’t that generally a part of the experience?

I don’t have a good answer. I know I’ve had problems with this – I’m clearly in the high risk category for hyponatremia. I also generally have particularly poor races if it is a warm day.

My interventions include

1.) Drinking enough water
2.) Electrolyte supplements in my water (NUUN, Gu Brew)
3.) Additional electrolyte supplementation (SaltStick caps, Endurolytes caps, little pretzels)
4.) Making sure I have a salty snack or meal after a race or long run
5.) Trying to dress so I’m a little cool rather than a little warm

I’d love to read your suggestions – please leave a comment if you have any experience with hyponatremia and suggestions as to how to avoid it.

Update (March 13, 2014):

I found this terrific article posted on Twitter by Dr. Larry Creswell. The key points are quoted below.

KEY POINTS

Most medical scientific organizations recommend low or moderate sodium diets to the general population in order to reduce the risk of high
blood pressure (hypertension).

Regular physical activity reduces the risk of hypertension.

Athletes lose sodium in sweat during exercise. The amount of sodium that is lost during endurance exercise depends on the sweating rate and
the concentration of sodium in the sweat. In turn, sodium loss during exercise depends on individual factors, such as genetics, fitness and heat
acclimatization, as well as the type, intensity and duration of exercise and the external environment.

Sodium ingestion by endurance athletes does not typically increase blood pressure, so low sodium diets are not recommended for individuals
who participate in long-term aerobic exercise.

Sodium ingestion during or following endurance exercise will help to stimulate thirst and drinking as well as stimulate fluid retention by the kidney.

No athletes are immune to hypertension, so athletes should monitor their blood pressure as they do their general health. This is particularly
important for older athletes, athletes with a genetic predisposition to hypertension, stroke or other cardiovascular disease.

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Race Report – Bizz Johnson Trail Marathon, October 13, 2013

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Runners at the starting line 2013
 
This year, October 13, 2013, was my seventh time running the Bizz Johnson Trail Marathon. My first time was in 2007 and I have ran the event every year since then. Last year I ran the 50K (31 miles), but it is pretty much the same course, just 5 miles longer.
 
Has anybody reading this blog knows I have been in persistent atrial fibrillation for the last two years. For the 50K last year, and the marathon this year, I was in known atrial fibrillation. I am pretty sure that I went into atrial fibrillation about two thirds of the way through the 2011 marathon. At least (in retrospect) it felt that way, but that was before I knew I was afflicted with this dysrhythmia.

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It took a long time to get to the finish line this year
 
The course of the Bizz Johnson Trail Marathon is well known to me and I enjoy it a great deal. The Bizz Johnson Trail is a rails to trails project, and is about 24 ½ miles long. For that reason the race begins with an out and back on a Forest Service fire road in order to make the marathon and official 26.2 mile run. Once the runners get on the actual rail trail the course is a gentle uphill until about the 6 mile marker at which point there is a 20 mile downhill section. This might sound like it’s easy, but remember, it’s a run not a bike ride. This is the only race where afterward I typically have a lot of quadriceps and heel pain from all the downhill.

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Except for the portion where the trail crosses the Susan River Canyon the grade is very gradual. Trains evidently are unable to go up or down anything that is too steep, and the average grade is below 1%, and at its steepest probably about 2%. This is an estimate, I’m really not sure of the exact grade. One thing I can say, though, is that the steepest downhill is the last 6 miles down the Susan River Canyon. This is also where the course is the most scenic (including two tunnels) and often this section is quite warm.
 
This year the deciduous trees were changing and it was quite beautiful.

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Along the course (No deciduous trees here – sorry)
 
Some people worry about the elevation at Bizz Johnson, but to me that isn’t even a factor. I live and train at the exact same elevation as the Bizz Johnson Trail. As a matter of fact I do almost all my training on mountain biking and hiking trails which are much steeper and more technical than the Bizz Johnson Trail.
 
I have to admit I had a bad time this year. I don’t think it had anything to do with the atrial fibrillation per se, I think I worked myself into a bad attitude, or bad mental state this year – ruminating over certain past events on the two and a half hour drive to Susanville the day before the race. Also I had trained for the 50K, but I really didn’t feel up to it and the day before the race I switched to the regular marathon. This probably was a good move, but I felt somehow depressed over that choice.
 
I’m not sure how many marathons I have ran, but it’s somewhere between seventeen and twenty races. There comes a time in every marathon where I start to feel poorly, but usually I don’t start to feel that way until somewhere around mile twenty-two or twenty-three. For some reason at this year’s Bizz Johnson I started to feel that way about mile six. “It’s going to be a long day,” I told myself.


 
Ultimately I completed it, I suffered like an animal, but I lived to fight another day. It’s interesting that I finished it at almost the same time that I finished the 50K last year, that is taking into consideration that the 50K starts an hour before the regular marathon. My recollection of the 50K last year is that I felt much better, surprisingly, throughout the entire race than I have during any previous marathons. Maybe I should stick with 50Ks.
 
My friend Stephen, who ran the race this year as well, said he suffered like an animal as well, and that “it seemed like every mile hurt.” But then again he finished several hours ahead of me, came in seventh place overall, and won his age group. It was probably worth it.
 
Sometimes I wonder – am I good at marathons? Maybe. Maybe not. I’m certainly not fast. Seems like I did a good job, the night before, sitting in a motel room watching sitcoms. Maybe I’m better at something like that. Well, I guess I’ll have to keep trying marathons until I get one right.
 
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Finishing the 50K last year

Being a veteran trail runner who has to be self-reliant, except during a race, I carry my own water. I use an Ultimate Design WASP hydration vest, with NUUN tablets added for electrolytes. I refill it at the water stops if necessary. This year, for some reason, I figured I should probably drink some of the electrolyte drink that they offered at the water stops in addition to my own concoction. I should have known better. It was a pink drink that is evidently marketed by the Power Bar company. I have never tasted a urinal cookie before, but I imagine that this pink sports drink is pretty close. Every time I drank a Dixie cup of it at a water stop I had to walk a little bit and try to hold it down. In other words I was having a lot of nausea. Being nauseous will not prevent me from drinking because I figure I can always drink more water if I vomit, but it sure does keep me from eating, so I was a little deficient as far as carbo gels were concerned. I think I only had two all day (and had planned on five).
 
During last Sunday’s race I decided that the mile between mile marker twenty-three and mile marker twenty-four is definitely the cruelest mile. Suffering is maximized, and you’re close but not really close enough to the finish. If I tell myself, “it’s only three more miles!” I then start to think that three miles sounds like a terribly long distance.

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I enjoy listening to music on my iPod shuffle while I run and when I arrived at the last quarter mile of the race a terrific song came on my iPod. It was Oh Comely by Neutral Milk Hotel. Unfortunately I was feeling remarkably emotionally labile at that point in time that I knew that if I listened to the song I would start crying. I already knew I was suffering and wasn’t going to appear well coming across the finish line, but I really didn’t want to finish crying like a little kid – so I fast forwarded it. I clicked until I found a song that was a little bit more emotionally bland.

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When the finish line mercifully appeared I was glad to be done. I strolled over to the feed section and as usual there were a lot of great things to eat, but I was feeling so nauseous – there was not one thing there that I could’ve eaten. Claude, who also ran the race that day, was waiting for me and we took the shuttle back to the parking area. I had some food in my truck for post race meal, but as soon as I walked over there I became quite sick and expelled a large quantity of pink water. It must have just sat there in my stomach – there was a lot of it! I felt much better, changed into my dry clothes, and ate my post race meal. I started to wonder – emotionally labile, tearful, and nauseous – was I pregnant? (Ha ha)

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Heat and Salt and A Fib

As stated previously I get pretty lightheaded when I get up from a sitting position after a hard workout, particularly in hot weather. Orthostatic hypotension. I don’t know why I get dehydrated so easily now, but I have learned that I need to eat something salty and drink a lot of water  after a workout, particularly a run or a bike ride which is longer than an hour or two, otherwise I get pretty dizzy when I first standup, and I’ve had a friend who is an nephrologist and another friend who is an internist both tell me to make sure I drink plenty of water after a workout and get some salt. Just one more fun aspect of being in persistent atrial fibrillation.

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Pre-Race Motel

This is the first time in my life I’ve ever actually been trying to get more salt. Most people spend their lives trying to avoid salt. I have started bringing potato chips for a post run snack to the trailhead for my long runs. Another great post run snack is some blue corn chips with some hummus with some Hoisin sauce.

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Pre-Race

Although it is neither here nor there, I’d like to state that I am a vegetarian (nearly vegan – if not for the occasional veggie pizza) as far as diet is concerned.

I also find that I am more sensitive to heat, which is obviously related. Last summer I would often start to feel pretty tired 17 miles into a 20 mile training run. In cool weather a 20 mile trail run is no problem. When I’m training for a 50K I basically try to do a 20 mile run every weekend.

Fortunately I live in Klamath Falls, on the East side of the Cascades of Oregon, where we have relatively cold Winters and generally cool Spring and Autumn. Summer, obviously, can be pretty hot – but nothing like Southern California, Arizona, Mexico, the South, etc.

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Resting During a Trail Run

I have also noticed over the past several years that I did quite poorly during marathons if the weather got hot. The concept of hot weather is a relative term – for me anything over 70°F (21°C) would be considered hot. My ideal running weather would be 35 to 55°F. Ten years ago I could do a 20 mile run when it was 90°F (32°C) without much problem. Those days are over.

I’d be interested in hearing from other people with atrial fibrillation with respect to this. Please comment.

ringotired

Ringo – Pooped Out After a Long Trail Run