Send letter to journal:
Re: Re: An Erroneous Conclusion

We are pleased that Dr. Shephard agrees with our views. In contrast to his retrospective assertions, dispassionate analysis of what he has written in the past shows that his conversion to our drinking guidelines has occurred only with the publication of his most recent letter.

Professor Shephard continues to be dismissive of most of the work of our Cape Town research unit [1, 2]. To our knowledge we have largely single-handedly led the battle against overdrinking [3-6] beginning with our 1985 paper [7]; we are not aware that Professor Shephard ever contributed to that campaign although we obviously welcome his belated support. To state that this is a “relatively new insight for investigators in Cape Town” is perhaps the most remarkable distortion to be published in the British Journal of Sports Medicine in the past 40 years that the senior author has been reading this journal. It brings to mind the famous statement to the effect that truth goes through three distinct phases. First other scientists say that what you claim is completely wrong. Next they acknowledge that your claim is indeed true but they continue to dismiss it as “completely irrelevant”. Finally they claim your truth as their own declaring that “we always said it anyway”. About six years ago Professor Shephard concluded that the drinking guidelines in Lore of Running [8] were completely wrong, perhaps dangerous. Now apparently he was the first to propose those identical guidelines “26 years ago”.

Our analysis of what appears in Professor Shephard’s book is not “totally incorrect”. His book is cited only once in our paper (table 1) [9]. The book does not provide a set of drinking guideline for athletes. Instead at different parts of the text, there are references that Professor Shephard now claims can be cobbled together to produce a set of drinking guidelines. For example his assertions 1 and 3 in his letter (pp. 42 and 72 respectively in [10]) are not drinking guidelines. Assertion 2 is also not written as part of a drinking guideline. Rather it appears as part of a review of previous work of fluid intake and runners. For example on page 43 of his book Shephard writes: “…Kavanagh and Shephard (1977a) followed middle-aged men over a 4- to 5-hr run; their group sustained a fluid intake of up to 630 ml.hr-1, the largest volumes again being ingested by those who were provided with pure water” [10]. Nowhere in his text does Professor Shephard define optimum rates of fluid intake during exercise, what we would consider a core component of responsible drinking guidelines. Of course providing specific drinking guidelines involves personal accountability and not everyone is prepared to accept that responsibility.

A more complete examination of the book reveals further examples of advice that is so vague that it is of little value. For example on page 42 Professor Shephard writes: “the water balance of a distance runner or team sportsman can be improved if he is preloaded with up to 500ml of fluid 15-30min before exercise commences. Further small quantities of fluid should be taken at regular intervals as exercise proceeds” [10].

Finally in contrast to Professor Shephard’s certainty that his book does not contain advice which would encourage athletes to “drink beyond thirst”, page 309 contains the following specific advice: “During exercise or heat exposure, thirst is not a sufficient indicator of fluids needs (Adolph, 1947)”. Thus Professor Shephard’s book like most of the other material that we reviewed, does indeed promote overdrinking.

In summary, one of the points of our article was to show how textbooks can perpetuate old and often out-of-date advice. Professor Shephard’s response extends that argument by showing that some authors are unaware of exactly what is in their own textbooks and how dated and incorrect that advice might be.

References

1. Shephard RJ. Do the Numbers Add Up? Clin J Sport Med. 13(3):192, May 2003.

2. Shephard RJ. Hard evidence for a Central Governor is still lacking! J Appl Physiol, in press 2008.

3. Noakes TD. Drinking guidelines for exercise: What evidence is there that athletes should drink “as much as tolerable”, to “replace the weight lost during exercise” or “ad libitum”? J Sports Sci 2007;25(7):781- 796.

4. Noakes TD, Sharwood K, Speedy D, et al. Three independent biological mechanisms cause exercise-associated hyponatraemia: evidence from 2,135 weighed competitive athletic performances. Proc Nat Acad Sci USA 2005;102(51):18550-18555.

5. Hew T, Almond C, Ayus C, et al. Consensus Statement of the 1st International Exercise-Associated Hyponatraemia Consensus Development Conference, Cape town, South Africa 2005. Clin J Sport Med 2005;15:208- 213.

6. Noakes TD, Martin DE. IMMDA advisory statement on guidelines for fluid replacement during marathon running. New Studies in Athletics 2002;17(1):15-24.

7. Noakes TD, Goodwin N, Rayner BL, Branken T, Taylor RK. Water intoxication: a possible complication during endurance exercise. Med Sci Sports Exerc. 1985 Jun;17(3):370-5.

8. Noakes TD. Lore of running. 4th ed. Champaign, Il: Human Kinetics, 2003.

9. Beltrami FG, Hew-Butler T, Noakes TD. Drinking policies and exercise-associated hyponatremia: is anyone still promoting overdrinking? Br J Sports Med 2008; 42:496-501.

10. Shephard RJ. Physiology and Biochemistry of Exercise. New York: Prager Publications, 1982.

Send letter to journal:
Re: Textbooks and drinking policies

Dear Sir

There is one recent textbook which explains the problem and promotes 'sensible' drinking policies.

Grant S, Lloyd E. Training and Performance in difficult environments. Crowood Press 2006.

ISBN-10 1 86126 881 5 & ISBN-13 978 1 86126 881 5

This was published in Dec 2006 and is planned to be readable for competitive and social athletes, coaches, physios and doctors both sports medicine orientated and general. It covers physiology and science at practical levels, and covers the drinking controversy in considerable detail.

Send letter to journal:
Re: An Erroneous Conclusion

Beltrami and colleagues are correct to castigate the continued over-ingestion of fluids by marathon runners [1]. This may be a relatively new insight for investigators in Cape Town, where reports of over-hydration first surfaced. However, if the authors of the present report [1] will reread my textbook (wrongly described as published in 1974!), they will discover that it contains advice on fluid intake for distance runners, advice which in my view requires little modification in 2008 [2]. The topic is discussed in chapters 2 and 3 of the cited text [2]. Among the recommendations that were made some 26 years ago are:

recognizing that a cumulative weight loss of up to 2 kg is compatible with euhydration over the course of a marathon run,

allowing ad-libitum, thirst-guided drinking of up to 600 ml/h of water or other fluids during the course of such an event, and

weighing of runners immediately before and after a race offers the best simple check on hydration status.

The interpretation of Beltrami and colleagues (p. 498) that advice in my text is either absent or falls within the range ‘from “drink to match sweat rates” to “drink beyond thirst” ‘ is unfortunately totally incorrect.

References

1. Beltrami FG, Hew-Butler T, Noakes TD. Drinking policies and exercise-associated hyponatremia: is anyone still promoting overdrinking? Br J Sports Med 2008; 42:496-501.
2.Shephard RJ. Physiology and Biochemistry of Exercise. New York: Prager Publications.