Waterlogged – A Dogma-Shattering Book?

Stay the CourseDogma-shattering: an idea integral to the creation and evolution of ultrarunning – a sport created out of the notion that we could run longer and farther, beyond road and track, than anyone believed was possible.

Modern trail ultrarunning was borne from the notion of refusing to accept the belief that no one could run a hundred miles through the mountains in a single day. Done.

Then, no one could run all the uphills in that fabled Sierra Nevada foot race. Done again.

No one, let alone a woman, could cover 47 miles a day for weeks and months on the Appalachian Trail. And no one, period, could eclipse the fifteen-hour barrier at Western States. Done, and done.

Ultramarathon running has pushed the limits of conventional wisdom on all things in human performance: distance and speed, nutrition, and even footwear. Indeed, it was the tales of the rubber tire-shod indigenous ultrarunners of the Copper Canyons that fueled the mainstream adoption of minimalist running, smashing the dogmatic belief in the necessity of hyper-engineered shoes.

It is fitting, then, that the sport of ultramarathoning be ground zero for more dogma-shattering in another area: hydration in endurance exercise.

A new book by renowned sport medicine expert, Tim Noakes, MD, aims to change our beliefs – many of them longstanding, many of them inaccurate – on what it means to fuel optimally in endurance sports:

  • Drink only to thirst, not on a schedule.
  • Drinking does not prevent heat illness.
  • Ingesting salt is unnecessary in ultras.
  • Urine frequency or color has nothing to do with hydration or kidney function.

Say what? Them’s fightin’ words!

Noakes knows it, but he’s ready for the fight. And, with his background, there’s no one better armed. Dr. Noakes has been studying running and endurances sports for nearly fifty years. He has authored or co-authored over 250 scientific studies, including over fifty that examine the role of hydration and electrolytes in sports performance. In addition to sitting on the boards of the American College of Sports Medicine and the International Olympic Committee’s Science Academy, he’s also an experienced ultrarunner: having raced over seventy marathons and ultras, including the famed Comrades Marathon in his native South Africa. One could argue that he wrote the book on distance running: his Lore of RunningLore of Running is one of the most thorough, expansive scientific work on running, and, in its fourth edition, it is standing the test of time.

It was his work with Comrades that first sparked his interest in fluid replacement science. In 1981, Noakes received a letter from a Comrades participant describing her acute illness and hospitalization after that race, the result of drinking too much.

This perplexed and troubled Noakes: he subscribed to the early studies showing relationships between body temperature and weight loss, and was an early proponent of the “drink as much as you can” movement, pervasive to the sport in the 1980s and ‘90s. However, this letter – and mounting cases of Exercise-Associated Hyponatremia (EAH) – caused him to re-evaluate, not only his own beliefs, but also the existing research.

Combining empirical research, fundamentals of human physiology, and numerous performance studies, Waterlogged is an exhaustive look at the research, past and present, the origins of the “dehydration myth” and the role of industry in its propagation, and what athletes really need for optimal performance and safety.

An Argument for Self-Regulation                                          

At its core, Waterlogged is a work that sets out to defend the fundamental biological quality of self-regulation – the idea that the body possesses mechanisms to self-regulate its own physiology to survive any physical challenge, no matter how extreme.

For various reasons – flawed or misinterpreted research, personal beliefs, or outright fear – many people – scientists, physicians, and athletes, alike – began to adopt the “catastrophe model.” Dr. Noakes describes it herein:

“According to this catastrophe model, the body cannot accommodate even small increases in body temperature during exercise, nor can it adjust to the fluid and sodium deficits that develop as it loses both in sweat during exercise. Instead, when exposed to exercise under demanding conditions, the body will simply continue without control until eventually a catastrophic physiological failure must inevitably develop.”

Based on this belief system, the sports medicine community – ranging from doctors to coaches and athletes – has recommended that all exercisers must avoid deficits of fluid – as well as salt and glucose –at all costs. Moreover, this belief system insists that our built-in controls are “hopelessly inadequate,” and that only by overriding these controls can we as athletes avoid catastrophic failure – ranging from DNF to death.

Indeed, this belief system – pushed powerfully by a burgeoning sports drink industry – fueled radical changes in how we fuel for endurance exercise. Within a few years, our drinking habits changed from “not a drop” to “drink as much as you can.” And not without consequence.

The Emergence of Hyponatremia in Endurance Sports

Exercise-Associated Hyponatremia (EAH, or simply hyponatremia) is a condition of decreased blood sodium concentration. Once exceedingly rare if not unheard of during endurance exercise, EAH has exploded in incidence across all events, ranging from marathons to triathlons, to even shorter sub-marathon events.

Its symptoms – weight gain, swelling, nausea and vomiting, headache, muscle cell breakdown, altered consciousness and seizure – were, for years, erroneously attributed to either heat exhaustion or dehydration. As such, EAH was incorrectly treated with the exactly the thing that caused it – more water!

The results can be dangerous and deadly. Excess water causes muscle cells to balloon and burst. It drowns nerve cells. But left unabated, the water accumulates in the confined space of the skull, causing brain tissue to herniate – the brain stem pushes its way out the base of skull, causing death.

Recreational athletes – running easy, in cool temperatures, minding recommendations to “drink as much as you can, to drink before you’re thirsty!” – began showing up in the hospital instead of the finish line.

Some of them were dying.

Hyponatremia was nearly non-existent before the 1970s. Where did it come from?

The Florida Panhandle: Where Dogma – and The Sports Drink Industry – Was Born

Waterlogged tells the story of the creation of Gatorade, the world’s first electrolyte drink. In August of 1965, an assistant football coach for the University of Florida, Dewayne Douglass, shared lunch with a renal scientist, Dr. Dana Shires, at the university, where the coach described his team’s struggles with “heat exhaustion and dehydration.” In that meeting, he implored the scientist and her team – which included renowned renal scientist Robert Cade – to develop “something to negate the strain of the brutal summer heat.” She returned to the lab, conferred with Dr. Cade and within two months, an experimental electrolyte solution was field tested: first with a freshman and varsity B-team scrimmage, and then in a real contest between the Gators and Louisiana State. Based on those two outcomes – second-half “rallies” by both the downtrodden freshman and the underdog Gators – the Legend of Gatorade – was born. The drink was adopted by college and pro teams, alike, and a new industry developed.

It doesn’t take a PhD or a background in research to determine the flaws in this experiment: the lack of any controls and the inability to control placebo effect: the players were given a drink that, coaches insisted, would help.

(It’s worth noting by Dr. Noakes that the success of the ’65 and ’66 Gators also included stellar play from legendary quarterback and future coach, Steve Spurrier, who won the Heisman Trophy in ’66. More notable is that Spurrier drank Coca-Cola, not Gatorade, during games!)

Later studies of Gatorade – performed years after the drink was successfully marketed and sold to masses – demonstrated only that ingesting glucose during competition was beneficial. Every subsequent study of Gatorade failed to demonstrate any significant benefit from the ingestion of either water or low-concentration sodium on core body temperature, blood sodium concentration, and performance.

In some cases, of the opposite was found.

The Tipping Point of Overhydration & Endurance Running: the Wyndham and Strydom Studies

One of the early studies examining hydration, core temperature and weight loss was conducted two South African researchers, Cyril Wyndham and Nic Strydom. Pre-eminent researchers in thermoregulation, they decided to study the role of hydration and marathon running. Their 1969 study found a loose correlation between rising core temperature and percent weight loss during marathon running. Based on those findings, they concluded that dehydration caused core temperature increases, and that, allowed to continue unabated (read: catastrophe model), runners are at high risk for heatstroke unless they drink.

Based on their study, they inferred that the optimal fluid for marathoners to be nearly a liter per hour – roughly two to three times that of previous studies, and an order of magnitude greater than what the elite marathoners of ‘60s were ingesting – in order to prevent the “dangers” of heatstroke.

Initially, the study was tough to argue: it showed a neat, linear relationship between water deficit and core temperature, indicating that any level of dehydration equated to core temperature rise.

But their study was flawed:

  • The runners they examined were not allowed to drink any water – rather than compare multiple levels of hydration, they studied only a group that disallowed any fluid.
  • The runners were advised to run as hard as they could; their efforts were not controlled.
  • There was no correlation of race performance with dehydration and core temperature. This is notable, because the winners of these race studies also happened to have the highest core temperature and weight loss.

Perhaps pressured to release this data and save the masses from impending danger, Wyndham and Strydom failed to execute a thorough study. That, coupled with the emergence of an industry giant replete with anecdotes of athletic prowess, was enough to spin the cogs of hydration dogma for decades: “Drink before you get thirsty! Replace all fluid and electrolytes lost during exercise!”

Evidence-Based Findings

Noakes began to review the literature pre-Wyndham and Strydom, as well as studies that occurred in its aftermath. Moreover, he conducted his own work. Waterlogged lays out this work dissecting the bad from the good, and presents it to the reader in plain view. Studying events ranging from the standard marathon to hundred-mile and 24-hour endurance competitions, Noakes determined the following:

The Role of Hydration and Performance

  • Dogma: In order to ensure optimal performance and/or survive endurance events, one must replace all lost fluids by drinking during the event.
  • Science: Fluid (and weight) loss during endurance exercise is normal, if not optimal.

Noakes notes that studies of top performers in endurance events (marathon, triathlon and long-ultras) typically demonstrate weight losses ranging from 2% to upwards of 8% or higher. More notable, weight loss was correlated to performance in these studies. Conversely, weight gain is correlated to impaired performance and – in most cases – a clinical sign of EAH.

The explanation of these findings is two-fold: first, that sugar (in the form of blood glucose and liver and muscle glycogen) is stored with surrounding water, and that when we burn that sugar, the water leaves with it. Therefore, a significant degree of weight loss due to burned glucose and freed water is normal. This value is now accepted to be in the 2% range.

Second, a significant volume of fluid lost during exercise – through vapor, sweat, or urine – comes from extracellular fluid (ECF). This fluid lies in between cells, as opposed to water found within cells (intracellular) or within blood volume (previous studies have shown that upwards of 70-80% of fluid losses are from ECF and glucose storage, not cellular or plasma water).

Therefore, we stand to lose significant volumes of water weight via sugar storage and ECF without physiological – or performance – consequence.

He argues that only when weight loss is coupled with uncorrected thirst, does performance impair due to dehydration.

Hydration and Thermoregulation

  • Dogma: We must drink water in order to prevent heat illness during exercise in hot conditions.
  • Science: There is no relationship between fluid intake and hydration, and the incidence of heat exhaustion or heatstroke. The only correlate to core temperature is running pace.

Noakes cites volumes of research studies athletes across all sports and events: American football players, marathoners, ultrarunners, and recreational walkers. There is not a single study that demonstrated a difference in core temperature between athletes who drink and those who do not. Nor has there been any evidence – empirical or case study – that links heat exhaustion or stroke to high levels of fluid loss, sodium loss, or the cessation of sweating.

Instead, the only behavioral factor that influences core body temperature during exercise is effort. Again citing the physiological theory of self-regulation and empirical study, Noakes points out that the body will automatically adjust pace in order to ensure that core temperature does not exceed normal thermoregulation (deemed to be <40-42⁰C).

Only pace – dictated by the degree to which our muscles work, burning energy and generating heat – determines core temperature. As such, the athletes who ran the fastest – and won – had the highest core body temperatures, with correlational fluid losses.

It is notable, however, that additional evaporative and external cooling measures – such as ice packs and water dousing – do result in changes in tissue temperature. Indeed, the only acceptable medical treatment for acute heat illness is external cooling via ice packs – not the administration of intravenous fluids, as some may believe.

Heat illness, namely heatstroke, is extraordinarily rare in endurance sports, Noakes points out. Using the clinical definition – a core temperature above 42⁰C, he identifies only six documented cases of heat stroke during endurance (marathon or above) since 1905.

Heat exhaustion or heat stroke is far more common in shorter running events, in large part because the intense efforts and short durations of these events merge to create temperature increases before the body can self-regulate pace. In the vast majority of cases, the heat illness quickly resolves with rest and, when necessary, cooling measures.

Dr. Noakes points out that in most cases of fatal heat illness, there exists an abnormal mechanism of heat build-up – excessive endogenous heat production – whereby the body goes haywire, producing heat, regardless of external temperature or duration of effort. Says Noakes, “this is the only explanation for the large number of cases of heatstroke that occur in cool conditions, or in athletes exercising at a low intensity, or those who have been physically active for only a short time, or in those who have been actively cooled for many hours.” Moreover, some cases have shown insidious spikes in core temp, hours – if not days – after cessation of exercise and onset of treatment.

The high incidence of heat stroke in short distance events – versus virtually none marathons and ultras – also shines light on the lack of connection between hydration and core body temperature. That heat illness is so prevalent in short-lasting events – where very little fluid is lost, yet there is next to no incidence in multi-hour efforts, even with profound water loss – is telling.

Sodium Balance and Performance

  • Dogma: We need to supplement with sodium to complete long-distance endurance events.
  • Science: The body self-regulates blood sodium concentration via several mechanisms, including sodium sparing in sweat and urine. When one “drinks to thirst,” blood sodium concentration invariably rises during prolonged exercise; it never falls.

One of the most persistent beliefs in ultrarunning is that we must ingest sodium for optimal performance, if not survival. Not so, claims Noakes. He points out several studies, including sodium deprivation studies involving prolonged exercise over several days, that demonstrates that the body will maintain blood sodium levels in a deprivation state.

In explaining this phenomenon, Noakes points out our biological mechanisms to preserve sodium in both sweat and urine – pointing out that these studies measured sodium concentrations next to nothing during prolonged exercise and sodium deprivation. Moreover, blood sodium concentrations stayed within normal ranges – so long as athletes and subjects drank only to thirst.

  • Dogma: Heavy sodium concentrations in sweat – evidenced by salt-staining on skin and clothing – identifies a person as a “salty sweater”, and that these people need even more sodium supplementation.
  • Science: The self-regulation of sodium concentration results in sodium excesses being secreted; salty secretions will cease when sodium balance is achieved.

Simply put, the presence of salt deposits on skin and clothing are due to the body ridding of excesses, and when sodium balance is achieved – or if a blood sodium deficit is perceived – the body will conserve it from sweat and urine.

  • Dogma: Sodium supplementation stops and prevents Exercise-Associated Muscle Cramping (EAMC)
  • Science: There is no scientific evidence that shows sodium (or other electrolyte) deficits in those with muscle cramping.

This is another interesting dogma that has thrived, pre-dating even Gatorade. The original belief of salt deficits and cramps was based, according to Noakes’ review of research, on studies of a single miner in the 1920s, who showed salt and fluid losses in association with cramps.

Noakes points out many studies that not only fail to show an association, but demonstrate normal – if not mildly elevated – blood sodium concentrations in those with muscle cramps. Conversely, it is well accepted that those suffering from hyponatremia do not suffer from muscle cramps – the very patient population that would, in theory suffer the most cramping, should a sodium deficit truly cause cramping. Internal or external temperatures also do not play a role, as EAMC occur in cool conditions (including extreme cold water swimmers).

Interestingly, more recent studies have even shown that ingesting electrolyte drinks actually increase cramping incidence: a 2005 study found a 68% incidence of those drinking Gatorade, versus a 54% drinking water, or nothing. And there may be a reason for that.

The current leading theory on muscle cramping is that neuromuscular fatigue – and the loss of inhibitory reflexes – causes excessive muscle activity, resulting in cramping. Moreover, a 2011 study has identified those two risk factors for developing cramping: previous cramping experiences, and faster finishing times; not body weight losses or blood sodium levels. This could explain the greater incidence of cramps amongst Gatorade drinkers: if an athlete perceives protection from drinking it – along with the ergogenic aid of glucose solution – they will run more intensely, possibly resulting in more cramps.

Anti-Diuretic Hormone – the Lynch Pin in Hyponatremic Illness and Death

  • Dogma: The frequency and color of my urine will tell me whether or not I am adequately hydrated; I should continue to drink after exercise until I am able to urinate – to ensure optimal hydration and kidney function.
  • Science: The presence of excessive anti-diuretic hormone during exercises – referred to as Syndrome of Inappropriate ADH (SIADH) secretion – can cause overt fluid retention and resulting in concentrated or complete lack of urine, despite severe overhydration and hyponatremia.

Antidiuretic Hormone (ADH) is secreted during exercise to conserve water from urine, when the brain determines that blood sodium levels are increasing. When sodium levels are balanced, ADH secretion stops. This is the principal reason that, for most of us, we urinate less (or not at all) during prolonged exercise, or that we urinate a lot when well-hydrated.

For reason unclear to scientists, in a significant population of runners (measures as high as 13% of Boston Marathon runners in a 2002 study) exhibit excessive levels of ADH. This condition, referred to as Syndrome of Inappropriate ADH secretion (SIADH), causes athletes to retain water beyond physiologically need, despite potentially severe overhydration and hyponatremia.

These are the runners that may exhibit symptoms of EAH – swelling, weight gain, impaired performance and brain function – yet report either dark urine or none at all. Yet this has nothing to do with the integrity of the kidneys; it is the presence of high levels of ADH that result in the body holding onto this water.

The presence of SIADH – measured in blood lab tests – has been a common finding in the most severe cases of hyponatremia, including deaths. In short, ADH prevented any passage of urine.

To reiterate: there is zero correlation between frequency or color of urination and hydration, or kidney function. ADH controls whether or not the kidney produces urine. Therefore, runners attempting to ensure hydration or kidney function with copious fluids might be endangering their race, if not their health, if there is excessive ADH in their bloodstream, blocking urine production. Indeed, given that hyponatremia leads to muscles cell lysis (explosion due to swelling), one might be endangering his kidneys with excessive drinking during or after endurance events.

The only things we can trust to ensure adequate fluid intake, according to Noakes, is our thirst and, to a lesser extent, the scale. The absence of thirst and an increasing weight (either absolute, or relative) is evidence that additional fluid is unnecessary and potentially dangerous.

Treatment and Prevention of Exercise-Associated Hyponatremia

As dangerous and deadly as EAH can be, the treatment – if initiated promptly and correctly – is quite simple. Research and clinical application has shown that a simple 100-mL “mini-IV” of high-concentration saline solution (3.0% of greater) produces rapid recovery of even the severely hyponatremic – within minutes.

Notable are studies that found a simple ingestion of the same volume and concentration of sodium solution does not have the same restorative effect. It is not known at this time why simply ingesting sodium is less effective.

Either treatment is far cry from what many hyponatremic runners receive – both at medical aid stations and local hospitals, which is typically more fluid, or intravenous solutions with inadequate sodium concentrations – typically 0.9% or less. Noakes implores sports medicine officials – and public health officials, alike – to make a thorough and accurate diagnosis of a hospitalized runner before initiating any IV fluids.

Given this reality, it is even more shocking that a major ultramarathon, at one point, was offering default intravenous solutions, post-race, without any medical justification. It could’ve killed someone.

Evidence-Based Fueling Recommendations for Optimal Performance and Safety

Drink only to thirst.

According to Noakes and the body of research on hydration and performance, individual differences are too great to make blanket recommendations. The only gauge for fluid need is thirst; the only symptom of dehydration is thirst.

Having said that, Noakes goes on to recommend fluid intake in the range of 400-800ml per hour for athletes across all endurance events, ranging from marathon to 24-hour+ events. This value is determined from observational studies of hydration, performance, and incidence of hyponatremia. The low range is for slower, lighter runners; the high end for heavier, faster runners.

It might be worthy to define “thirst.” Clearly, severe dehydration will cause severe thirst. However, those athletes looking to stay ahead of fluid need might consider a similar notion: “If it tastes good, you need it.” Simply put: does water taste good? If so, this subjective assessment might be a more nuanced assessment of fluid need. Whether the converse (an overt absence of thirst, accompanied by a dissatisfying taste and appeal of fluid) indicates fluid satiation or excess, was not addressed by Noakes or his book.

Consumption of roughly 60g of glucose per hour during competition will improve performance.

Noakes has separately researched and reviewed studies on glucose supplementation and determined this value for greatest performance and gastrointestinal acceptance. Values upwards of 100 grams per hour have shown even greater benefit; however, this increasing sugar invites GI disturbance.

Supplemental sodium is unnecessary in endurance competition.

This conclusion, based on his work and literature review, will undoubtedly result in controversy in the ultra community. Noakes is careful to point out numerous studies demonstrating that blood sodium levels are maintained in absence of supplementation and outright deprivation, with prolonged exercise over many days. Moreover, he points out the absence of any study that identifies performance benefit from sodium supplementation; in fact, he points out two studies in the past decade that contradict the notion.

For the sports medicine community, he recommends the following:

Be very careful to make accurate diagnoses of troubled runners.

Runners who come into medical checkpoints, feeling dizzy while standing still on a scale, are more likely to be experiencing Exercise-Associated Postural Hypotension than any other ailment, says Noakes. It is the simple notion that – in that brief moment of pause – a runner’s blood pressure drops due to the cessation of running. The simple treatment is to elevate the feet over the heart, wherein recovery is rapid. There is no evidence that postural hypotension is due to dehydration.

More important is an accurate diagnosis of the hyponatremic runner. An athlete exhibiting the signs and symptoms of hyponatremia – weight gain, swelling, nausea and vomiting, headache, muscle cell breakdown, altered consciousness and seizure – must be accurately diagnosed. Administering a 100mL bolus of 3.0% sodium solution results in rapid recovery in nearly every hyponatremic runner.

Erroneously determining these athletes as “heat exhausted” or “dehydrated” may result in forcing fluid consumption, or the administration of hypotonic IVs. This “treatment” will only worsen the condition, prolong the suffering and recovery time, and in worst case, may even result in death.

* * * * *

For a text so replete with cold facts, Dr. Noakes’ passion for the message permeates the text. Certainly, he is passionate for the sport, being a veteran of the marathon and ultra distance. But elements of personal frustration, and even guilt over having pushed the “drink” message in his early days, are also felt by the reader. Personal accounts of death from overhydration are included in Waterlogged, not to sensationalize, but to better understand how something as innocuous as water, and the good intentions to avoid suffering, can result in deadly consequences.

For this reader, given what has been known – yet ignored – about hydration science for so long, justifies the strength of message. In the very least, hyponatremia can ruin the race day for runners and families. Worse yet, it could end a running career. Or a life.

It is fitting, therefore, that Noakes finishes his text by putting the hard data away and appealing to our common sense, by saying, simply: “Your body will tell you what it needs, if you just listen.”

Trust your body, and it’ll take you places. Just as it has always done for ultrarunners.

If 4,500 words aren’t enough for you, stay tuned to part two of our discussion on hydration and ultramarathons: “Hyponatremia & Western States.” There, I will share additional insights, including:

  • A Q&A with author Tim Noakes, MD
  • My personal account (a “n=1 case study”) of applying Noakes’ recommendations to the 2012 Western States Endurance Run
  • Insights from Marty Hoffman, MD, lead research director for the WS100, and from Kerry Sullivan, MD, medical director
  • What the impact of Waterlogged may have on Western States and other ultramarathons in North America

Until then, here’s to happier, healthier running.

Call for Questions

  1. Have you ever experienced symptoms of hyponatremia during a race? Have you ever been diagnosed and held at an aid station – or forced to DNF – by medical personnel?
  2. What is your experience with fueling (either water, salt or calories) “by feel” versus “by a schedule?”

[Disclaimer: The contents of this column as well as the author’s comments are provided for general informational purposes only and are not intended as a substitute for professional medical advice. Do not use the information on this website for diagnosing or treating any medical or health condition.]

Joe Uhan

is a physical therapist, coach, and ultrarunner in Eugene, Oregon. He is a Minnesota native and has been a competitive runner for over 20 years. He has a Master’s Degree in Kinesiology, a Doctorate in Physical Therapy, and is a USATF Level II Certified Coach. Joe ran his first ultra at Autumn Leaves 50 Mile in October 2010, was 4th place at the 2015 USATF 100K Trail Championships (and 3rd in 2012), second at the 2014 Waldo 100K, and finished M9 at the 2012 Western States 100. Joe owns and operates Uhan Performance Physiotherapy in Eugene, Oregon, and offers online coaching and running analysis at uhanperformance.com.

There are 100 comments

  1. cory feign

    tested this out. at silver rush 50, had no electrolytes of any kind for the first half. in the second half, had 2 saltsticks, just because i was carrying the caffeine+ version and wanted a little zip and that was the only source. around 35-40, had some perpetuem solids, again mainly for caffeine (caffe late flavor, which has some caffeine and sodium). so out of almost 12 hours, that's only 542 mg of sodium (~10-20 % of what's "recommended"). everything was fine.

  2. William

    I tested this out a couple weeks ago at the North Fork 50k. I did the same race last year using conventional hydration, sodium replacement, and carb fueling. At mile 28 I had to slow down ~1 min/mile due to the heat (mid 80's). This year, under similar conditions and similar fitness, I attempted to hydrate by thirst and not take any electrolytes beyond what is in standard GU. My carb intake was the same as last year however, I used GU gels instead of EFS liquid shot. With pacing similar to last year, I hit a wall at 26 miles. I became nauseous, got tunnel vision (something I've never experienced in 15 years of racing/training) and had cramps in my calves and hamstrings. My stomach was no longer able/willing to take in any carbs. I had to walk ~2 miles to the next aid station where I went to the med tent to cool off in an ice bath. After ~10 minutes of cooling off and eating some pickles I was able to continue and finish the race. My time this year was 35 minutes slower. All the time was lost in the last 5 miles. Note that EFS combines carbs with high concentration of electrolytes so you don't need to pop pills while racing. So, I had EFS+water last year vs. GU+water this year. I don't think my performance difference had anything to do with hydration as I consumed about the same amount of water both years. I was taking in calories roughly the same as well so I think this is really came down to an electrolyte issue.

  3. Eric Chamberlin MD

    Jesse,

    Some facts that are critical in interpreting your experience.

    The higher the humidity the less one can sweat, and the less effective sweating is at cooling your body. At 100% humidity the air cannot hold any water. The little sweat you produce will be pooled on your skin because it can't get into the air. You will feel hot as hell and as if you are sweating a ton because your body is drenched. Body weight before and after will show you are not actually sweating a lot. This is why ultras are held in dry desert heat where sweating is effective, not in the rain forest.

    You always lose more water than sodium in sweat. Sodium is valuable and aldosterone causes sweat glands to reclaim some of the sodium before it is secreted onto the skin and into the air. After sweating the ECF, including plasma, will always be hypernatremic (too much sodium relative to water-concentration), even though total body sodium is less ( weight). It often appears that a great deal of sodium is lost because you can feel it on your skin and it's very salty if you lick your skin. This is because the water is gone, into the air, not on your skin. To illustrate, take a quart of water, throw in a tablespoon of salt and taste it. Then boil the water off and lick the bottom of the pan.

    When you drink water it is briefly stored in the stomach. When it passes into the small intestines pancreatic secretions add sodium to make it isotonic so it can be absorbed. If you drink water that your body doesn't need it will sit in your stomach and not be released into the small intestine. Feels awful. If you take salt you can raise the concentration of the water in your stomach so that it is near isotonic. Under those conditions it can be absorbed passively directly through the stomach wall. You will feel better by having gotten water out of your stomach that your body wasn't absorbing because it didn't need it. . The proof of this hypothesis again lies in weighing yourself.

    I've had very similar experiences and this is my interpretation of them after reading Dr. Noakes book. Discontinuing sodium supplementation and drinking to thirst have been working well for me. Hope this is useful.

    Eric Chamberlin MD

  4. Stewart

    I'm not trying to be a smart ass, but I go 8 hours without peeing almost every single night while I'm asleep with no ill effects. I know sleeping is a lot different than exercise, but that's just something to keep in mind.

  5. Kurt

    Thanks for an excellent summary. Now I'll have to get the book. One effect of taking on salt I'd picked up was that it helps keep hunger & food processing working properly. The result was meant to be avoiding that horrible "I know I should eat but I really don't want to look at food" feeling, so having an indirect performance benefit by improving caloric intake. Have you seen any indication if this is yet more nonsense?

    1. OOJ

      Kurt-

      Based on many anecdotal reports – and personal experience – it's entirely possible (if not quite probable) that sodium supplementation provides benefits that supercede blood sodium levels and work on a different level, physiologically:

      – Is it purely psychological? A substantial chunk is (Google search "placebo effect" to see its strength in clinical pharma trials)

      – Is it neurological? Benefiting the nerve cell (brain, motor)?

      – Is it in the muscle cell?

      I'm not sure, but that's what Part II will discuss further.

  6. david

    All I know is that electrolyte replacement is critical during long periods of strenuous exercise. My product of choice is Endurolytes by Hammer Nutrition. They flat work to eliminate cramping.

  7. Geoff Clover (MD)

    Well there is certainly a lot of concern and confusion on this issue. I am a fan of Dr Noakes and The Lore is a serious text – I have read it several times and it has helped me tremendously in the pursuit of the Ultra. In my first attempts at Leadville I tried salt/agressive hydration and have come to the conclusion that salt is not all that helpful for me – except in very high heat (crewing at Badwater). Recently in the LV50 I ran my best yet on relatively less salt and fluid than usual despite some heat and nausea near the end when the water bag ran low – poor planning on my part. A few observations on the discussion so far:

    – ADH (AVP) secretion (and so free water retention) varies a fair amount (type A to D for nerdy types). It may be that our hydration strategy could be tailored to individual testing one day. In any event, I think it would be difficult to advise any one person without such data, inferential or otherwise.

    – I get Dr Whites concerns and agree that overinterpretation of Dr Noakes research may lead to dangerous practices. I think we all need to be very careful in our advice and comments, particularly to less experienced runners. Or to more experienced – who am I kidding?

    – Not sure if this was mentioned but NSAIDS can cause SIADH

    – Nausea and pain are powerful drivers of ADH secretion (perhaps the most powerful)

    – Thirst is difficult to quantify as there are hormonal and cortical drivers. ADH is one such driver, as are volume depletion, temperature and local humidity. Agree that training and experience will enable each of us to learn what our true thirst is in a given situation.

    Perhaps, in the end, we should take all this with a grain of salt ;)

    Geoff

  8. Mike Papageorge

    Joe,

    "Consumption of roughly 60g of glucose per hour during competition will improve performance."

    Does he talk about Fructose at all? Asker Jeukendrup has done research that shows you can get in 60g of glucose and an additional 30g of fructose, and that together they tend to leave the stomach faster than on their own. Wondering if he addressed that at all?

    1. OOJ

      I believe Dr Noakes did alude to sugar differences (albeit briefly): if I recall correctly, he noted that a significant difference (between sugars) has yet to be found consistently in the literature.

      1. Mike Papageorge

        Hmm… Perhaps not consistently, but check this out (he seems to no longer have a personal site):

        http://www.birmingham.ac.uk/staff/profiles/sporte

        For example, down in publications: "Oxidation of combined ingestion of maltodextrins and fructose during exercise. Medicine and Science in Sports and Exercise 37(3): 426-32, 2005. O65"

        He also covered the issue in this podcast (worth listening to as he explains the idea):
        http://competitorradio.competitor.com/2010/03/ask

        Its not new information either. He used to be with Powerbar and is the reason (from what I can tell) they use the sugar ratios they do in their gels.

        Personally I've been making my own gels at 60-80g malto and 30-40 fructo and not had much trouble. The lower values for higher intensity efforts…

  9. Brandon

    I disagree with you Ben. Humans were created to run longer distances than animals. I agree that the slower humans were killed by predators. But humans actually ran down game, because the animals couldn't sweat & they die of cardiac issues. There are african tribes that still run down animals by following tracks. The Raramari tribe in Copper Canyons have ran the mountains for hundreds of years. We humans were born to run long distances…really long distances. It wasn't until modern times that allowed us to not run as far & then our weight & health became very poor. Read "Born To Run"…it's an awesome book!!

  10. Chris Lassen

    Wow! Great info! As an ultra runner on a plant-based diet, I am always concerned with my health as well as fueling my performance. This article empowers me with the confidence to do both effectively. And supports my minimalist approach to both. Thanks for stepping out and smacking the hornets nest, needed to be done…

  11. Le Manchot

    Aaron,

    To "prove" anything is extremely difficult but it begins with hard data. Not to be disrespectful, but you have actually proven nothing. Your observational data is the weakest of all data sources and has no link to causation without associated hard data. Noakes presents hard data and interprets that data based on knowledge of the workings of human biology and, in this case, the endocrine system.

    If your cramping is due to electrolyte imbalance, perhaps you could point us all to the hard data that supports that conclusion. I expect that as you review the available data on the subject (as Noakes did) that you will find no such correlation or causation. There may be a placebo effect or some other pathway that salt intake can affect exercise associated cramping (EAC) but all the data available to date indicates that it is an overuse condition, not an electrolyte imbalance.

    Collaterally, if there were an association between EAC and electrolyte imbalance, it is likely that the staff at the Gatorade Sports Science Institute (GSSI) or other sports drink industry-funded researchers would have discovered it as I am sure they have tried. Perhaps the most insightful experiments have yet to be done but it has not been for lack of trying as the GSSI and other laboratories around the world are well funded by the multi-billion dollar sports drink industry. Noakes could find nothing in GSSI (or any other) data that establishes a repeatable correlate between supplemental salt and EAC let alone a causal mechanism to support the correlation. The BBC ran a documentary in July 2012 about the so-called "science" conducted by this industry. Unfortunately the program cannot be viewed online except in the UK. But suffice it to say that the documentary was not complimentary (http://www.bbc.co.uk/programmes/b01l1yxk).

    Given all of this however, there is no real downside yet discovered to ingesting supplemental salt, so if it feels like it does something for you then you will likely not be otherwise endangering your well being by using supplemental salt. And this is the advice I give to others: it is not going to hurt you but there is no data that indicates that it does anything. So, if you are culturally, mythically, observationally, superstitiously, or otherwise convinced that supplemental salt is key to your performance in endurance and ultramarathon events then by all means take it. The mental side of the equation, as we all know, is very important.

    You might also read the book- it is well written and although it does require a fair dose of technical and scientific thought on the part of the reader, it is still "palatable" to those not in the field.

  12. Eliot W. Collins

    When I was a kid growing up in the 50's and 60's, no one carried a water-bottle. Sports drinks had not yet been invented. The adults told us that drinking water while playing sports would give us cramps. I do not recall anyone ever getting dehydrated. No one took salt tablets and no one got hyponatremia either.

    I still have never taken a salt tablet, and I never need to drink water while training, no matter how hot it is. So far, so good.

  13. Gordy Ainsleigh

    Bob Lind, who was medical director of the Western States 100 for 26 years, has been doing battle with this guy in the world of science for decades, and frankly, I'm with Bob in thinking that Noakes can't think straight.

    There are so many variables in runners that these generalities just don't work. For instance: how much salt does a runner eat in their day-to-day life? A person with a high-salt diet doesn't have enough aldosterone and renin secretion by the adrenal glands to hold on to their sodium, so they have to take in a lot of it while they run. A person on a low salt diet has high aldosterone and renin because their body is used to holding onto any sodium it can get, so they don't need anywhere near as much sodium electrolyte (salt, basically) replacement as the runner who loves the salty foods.

    Noakes thinks that the body can change its Renin and Aldosterone (sodium-retention) chemistry any time it wants to. The facts are that the body can't change its renin and aldosterone production anywhere near as fast as a person can become de-salted (hyponatremic). Just ask the guy I carried out from below Peachstone (mile 76 on the Western States trail). He took 2 electrolyte caps every hour while running, so his body was used to plenty of sodium, and had consequently very low renin and aldosterone production. That day, he didn't take along enough electrolyte caps, and his electrolyte caps ran out at noon. He kept running until he fell at about 4 PM, and couldn't even hold his head up when I got there at 6. God only knows what would have happened to him if I hadn't come along. It was late in the day, no one was on the trail, and his girlfriend was afraid to leave him to get help because a bear or mountain lion could have just walked up and started chewing.

    People with different daily salt intakes have to take in salt differently during a race. Noakes is basically oblivious to this fact, and thinks that what applies to the elite runner who does 130 miles a week will apply to the person who has to work for a living and put in time with spouse and kids. And his concept that dehydration is desirable is simply ludicrous. Hyponatremia–low sodium–results from one thing: not taking in enough salt with the water one drinks; but how much is enough depends on a bunch of other things like how much potassium a person takes in (the more potassium a person takes in, the more sodium is needed to balance it out), how much they salt their food, how much they sweat, and how much sodium they lose in their sweat.

    This last issue–how much sodium they lose is sweat–differs hugely according to training experience and genetics: in 1982 I was in Portland OR going to chiropractic college and it rained on every one of my long Saturday runs. That was really different training than I got in 1974 on the very first Western States 100 ever run, when all my long runs were in horrendous heat.

    In 1974 it was 107 F on race day, and I ran just like Noakes wants everybody to run: I got so dehydrated it hurt terribly to urinate because the uric acid was so concentrated. I was going to quit at Devil's Thumb, but Diane Clagget Marquard, the reigning queen of endurance riding, was there with a lame horse, pulled me aside and gave me the Dr Bob Lind treatment: fed me salt tablets and water. A half hour later, there was no doubt that I would finish.

    Another issue that Noakes incomprehensibly ignores is age: the young body handles dehydration much better than the aging body.

    Okay, here are Dr Gordy's rules: If you are down on weight and you aren't thirsty, eat salt (forget the balanced electrolytes, you just need sodium) and drink fluids. If you are overweight, quit drinking. 1.5% is a good threshold to worry about on weight loss, and 3% on weight gain. On a hot day, it's always better to be a bit overweight than a bit underweight, because dehydration is probably just ahead. When it cools down or you slow down, you won't be sweating as much and you have to pay attention to being overweight. You can stop drinking or you can speed up and sweat more. The cardinal rule is this: if you aren't thirsty, aren't hungry, and you feel like shit, eat a big pinch of salt. And remember: there are a lot of highly-educated idiots out there.

  14. Uriel Fernandez

    I usually run 10 miles without drinking any water till I get back to the car. I’ve been doing this waterless running since I was a kid. I’m from a semi-desert climate. even after I read about the importance of hydration I still just drink small sips every 30 minutes on long runs. Known that I’m very ignorant about the hydration subject I have one more confession to make. I didn’t know anything about electrolytes. I’ve heard the basic stuff you can get from sports drink brands but I’ve never noticed any improvement on performance by drinking those electrolyte beverages.

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