It is a rare occasion when a non-fiction book is published by a highly respected and accomplished author that provides a detailed history, a thorough analysis, and well founded recommendations. It is even a rarer occasion when such a book is almost entirely ignored by the popular press. Such is the case with Dr. T. Noakes’ recent book – Waterlogged – The Serious Problem of Overhydration in Endurance Sport – a singularly stellar critical examination of the biology and physiology of human hydration, development of the sports drink industry, and the advent of of the profit-driven “science” of hydration and fueling for athletes. Given the fact that the sports drink industry accounts for over $3B in revenue per year in the US and that it is likely that there does not exist a single US resident that has not consumed at least one such “sports drink”, I find it curious that there are no reviews of this book in the popular press (e.g. NY Times, Washington Post, SF Chronicle, LA Times, Miami Herald, Boston Globe, Time, Newsweek, etc.) and other mainstream media outlets since it’s publication in May 2012. This reality is perhaps the best encouragement for an endurance athlete (or anyone for that matter) to read this book. One can only wonder why broad exposure of this book to the recreational endurance sport participant (the overwhelming majority of participants) is so lacking as this segment is the most susceptible to the dangers clearly outlined by Noakes.
I have now read this book twice and can heartily recommend that any endurance athlete put this book on their short list. It is well written and requires the reader to engage in a fair dose of technical and scientific thought, but the text is generally palatable to a non-scientific audience. I will not provide a detailed review here as there is a very nice comprehensive two part review by J. Uhan, Ph.D. on the ultrarunning site iRunFar with a fairly voluminous commentary by readers who are primarily ultrarunners. It is this commentary to Mr. Uhan’s review that reveals exactly how susceptible the general ultrarunning populace is to “pseudo-science speak” by the “sports drink/fueling industry”. Such susceptibility is not unique to ultrarunners.
Some take aways
The primary message of the book is that the largest physiologic life threatening danger in competing (or participating) in endurance activities and events is overhydration not dehydration. In fact, dehydration is essentially a non-problem as very few cases of incapacitating dehydration have ever been reported at events and there have been no associated deaths. Noakes calls dehydration a “non-disease” and a manufactured condition made up by the “sports drink/fueling industry”. Overhydration and the potential for exercise associated hyponatremia (EAH) and exercise associated hyponatremia encephalopathy (EAHE) are the most frequently observed dangers and have resulted in more than 1600 reported cases and numerous deaths.
Another primary message of the book, and one that is reinforced in an interview with Noakes that I will link to below, is that the human body is a success not a failure. Much of the “sports drink/fueling industry” is founded on the basic concept that the human body is not able to cope with the stresses that we might put upon ourselves in either racing or just participating in an endurance event. Noakes presents a rich spectrum of data, analysis, and biologic mechanisms that refute such a position. He demonstrates that each of us possess inherent, finely-tuned, and effective responses to the onset of dehydration, reductions in electrolyte concentration, and heatstroke. Much of this can be traced to our unique historic human abilities as successful persistent hunters.
Although there is a distribution in how effectively each of our bodies can deal with such stresses, it is only a small fraction of the populace that may have issues in endurance events when following science-based (not industry-based) guidelines for fluid/fuel consumption. This is borne out by the fact that there were no epidemics of dehydration, hyponatremia, and heatstroke prior to the introduction of “sports drinks” and the associated high volume consumption guidelines as recommended by the American College of Sports Medicine (ACSM)- an organization that Noakes asserts is an apparent puppet for the “sports drink/fueling industry”.
One other observation that I take away from this book is graphically presented in Figure 9.9 (page 263). Here a graph of finishing time for Ironman triathletes as a function of percent body weight gain/loss is shown from data collected at the 1989 Hawaii Ironman Triatholon. Although Noakes fits a straight line to the data and asserts that there is no relationship, casual visual approximation of the data shows that an upward U-shaped curve might fit the data well. I fitted a polynomial to the data and found a reasonable correlation. The upward “U” functionality indicates that finishing time increases when an athlete is either over or under hydrated. Not surprising. However, what is shown (and what many athletes already know instinctively) is that there is an optimum level of hydration associated with a minimum finishing time. This value is about -3% body weight, in other words “substantially dehydrated” according to the “sports drink/fueling industry”. This observation is further confirmed when looking at marathon running finish times where it is found that the top finishers are consistently among the most dehydrated and typically dehydrated in excess of 3%. These and other data that Noakes presents indicate that, from a competitive perspective, it is desirable to exhibit a 3-5% dehydration at the end of an endurance event. Noakes gives some physiologic basis as to why this may be the case, not the least of which is that you are not carrying around as much weight and that your body has activated the biologic mechanisms that minimize the affect of dehydration on performance.
It is difficult to not feel the frustration that Noakes has with the “sports drink/fueling industry” and he leaves no question as to the techniques and mis-interpretations that have hoodwinked millions of people into using and abusing their products. These parts of the book may go on a bit too long but I think this may have been a part of a cathartic experience for Noakes to get all that he knows out there in print.
Other media sources on this book and Noakes’ work
There are a few recent interviews/videos that feature Noakes speaking about his book and his work and I have found the following worthwhile:
An audio interview which covers a lot of ground-
and this excellent BBC documentary (from July 2012) entitled The Truth About Sports Products. The documentary has specific focus on the “sports drink/fueling industry” where Noakes as well as numerous other respected scientists are featured-
Note 11 March 2016- the full documentary has been taken down but the approximately 11 minute excerpt from the full documentary with the Noakes interview is now available-
For me, one of the best scenes in the documentary is when Noakes is being interviewed and he is asked about the recent introduction by Coca Cola of Powerade Zero- a sugar-free sports drink. He cannot keep a straight face and the director continues to cue him up and he keeps laughing. He eventually gets it under control and proclaims that the mere existence of such a product is proof that they are no better than water for most users.
There is an overwhelming body of evidence showing that humans alter their behaviors to ensure that body temperature is homeostatically regulated regardless of the stresses, either internal (e.g. the level of hydration) or external (e.g. the environmental temperature) experienced. (p 11)
When glycogen is stored in liver and muscle, it attracts water molecules, which are released as the glycogen is used during exercise. In this way, additional water is released as that fuel is used during exercise. This water can offset some of the sweat losses. (p 32)
Humans developed as long-distance runners especially well adapted to run in extreme dry heat in the middle of the day while drinking infrequently and conserving body sodium stores. (p 35)
Thus the only symptom of dehydration is thirst. (p 44)
The point is that dizziness, fainting, and nausea are symptoms not of dehydration but of lack of blood supply to the brain. (p 54)
But either way, the fact that athletes with the greatest levels of weight loss are usually the fastest finishers in endurance events shows that the response of thier brains to body water loss has been entirely appropriate, perhaps optimal. (p 58)
… by the early 1990’s I had concluded that a myth had developed in the exercise sciences, the dehydration myth (p 89)
The authors concluded that how fast a person runs, not how much that person drinks, determines the extent to which body temperature rises during exercise. (p 99)
So it is an astonishing achievement of the sports drink industry that it has convinced us of the exact opposite– that modern human athletes lack biological controls to ensure that they ingest enough salt and so are at risk of developing a syndrome of salt deficiency even when eating a diet that is stuffed with salt. (p 107)
Not a single published scientific paper shows that blood electrolyte concentrations, including the sodium concentration, are abnormal at the time subjects develop exercise associated muscle cramps (EAMC). (p 118)
Evidence simply does not exist that recreational or professional athletes competing in long-duration events will inevitably develop a state of salt deficiency or dehydration. (p 144)
To suggest that the body cannot sustain long-term exercise in the heat without ingesting supplemental sodium ignores not only our biological design but also reams of research proving otherwise. (p 145)
If you wish to develop a medicine to cure or prevent an illness, then it is perhaps important to study patients with the illness or who have a predisposition for developing that illness when exposed to the causative agents. Alternatively, it is rather important that the illness you are trying to prevent actually exist and be caused by the mechanism you are studying. (p 184)
During this time EAH became the single greatest risk to the health of endurance athletes… (p 327)
- Your body will tell you what it needs, if you just listen.
- So drink only ad libitum – that is, according to the dictates of thirst.
- Dehydration is not a disease. Nor does dehydration contribute in any way to any illness associated with prolonged exercise like road, marathon, and ultramarathon running races an triathlons.
- If you are carbohydrate adapted, to optimize your performance during more prolonged competitive exercise, you will need to ingest some carbohydrate or perhaps preferably a favorite food.
- There is no need to increase your habitual daily sodium intake above that dictated by your appetite.
- There is no need to ingest additional sodium during exercise.
- Understand that much of what you believe about your personal well-being is the result of targeted manipulations of industries whose principal focus is their commercial fitness and not necessarily your heath or safety. (p 353)
There is much in this book that will serve the endurance athlete well. Presented is a plethora of information from basic biological function information to a thorough review of available data on hydration to science-based recommendations on what and how much to drink and how to fuel. An excellent read and one that you will likely go back to regularly much as many of us do to Noakes’ other treatise – The Lore of Running.