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Thirst as a Signal for Fluid Intake

This is an excerpt from Waterlogged by Timothy Noakes.

My interests lie in medicine, science, and sports, not necessarily in that order, for which there is no apparent ancestral precedent. Both my maternal and paternal grandfathers as well as my father were involved in commerce in the northwest English seaport of Liverpool. My father's commercial interests brought him to Zimbabwe in 1946, immediately after the end of World War II, three years before I was born. In 1954 we relocated to Cape Town, South Africa, where I began my schooling. I have lived in Cape Town ever since.

My fate was to begin my medical training and a postadolescent interest in endurance sports in 1969, when the prevailing belief was that humans should not drink during exercise. Drinking during exercise, we were taught, was a sign of weakness. And should we succumb to our weakness, we would immediately feel discomfort and our pace would slacken. Our knowledge came from those whose wisdom, forged in the heat of athletic competition, had yet to be tested in the laboratory.

At the time, I was learning to row, not yet to run long distances. In training for rowing, we seldom ran farther than 3 km and then always at maximum pace. But one day when the wind was so strong that we could not venture onto the water, I opted to run around the lake on which we trained. That run was decisive: After 40 minutes I experienced the runner's high, seemingly touching heaven. I knew then that one day I would run a long-distance race, most especially the uniquely South African ultradistance running event, the 90 km (56 mile) Comrades Marathon. But that would happen only 4 years later.

In between these bouts of running, I rowed without ever considering whether or not drinking before, during, or after exercise was of any importance. We drank only after each workout, guided by our thirst. Our coach did not restrict our daily fluid intake to 1 L as happened to the Oxford rowing crew of 1860 whose “outraged human nature rebelled against it; and although they did not admit it in public, there were very few men who did not rush to their water bottles for relief, more or less often, according to the development of their conscientiousness and their obstinacy” (Hughes, 1861/2008, p. 108). Perhaps the author of those English classics Tom Brown's Schooldays and Tom Brown at Oxford understood that thirst is an extremely powerful sensation not easily overridden or ignored, for the body knows what it needs better than the coach.

Later I discovered that a century ago marathon runners received essentially the same advice: “Don't take any nourishment before going seventeen or eighteen miles. If you do, you will never go the distance. Don't get into the habit of drinking or eating in a marathon race: Some prominent runners do, but it is not beneficial” (Sullivan, 1909, p. 39).

The advice of American Joseph Forshaw, who finished third in the 1908 London Olympic Marathon in 2:57:10, was the same: “As to the taking of stimulants during the race, I will say that I know from actual experience that the full [marathon] race can be covered in creditable time without so much as a single drop of water being taken or even sponging of the head—I have done it myself. This of course is when in perfect trim” (Martin and Gynn, 1979, p. 45; Sullivan, 1909, p. 73). He continued, “I do not believe in eating during the race, as it can scarcely benefit one, as no nourishment can come from the food till digested, and the race will be finished before the food would be digested” (p. 73). We now know that this part of his advice is wrong: Eating does aid performance during prolonged exercise, at least in part because the digestion of food is not impaired during prolonged exercise.

Forshaw also wrote, “To cool the head and the blood in general on a hot day, sponge the head with bay rum, as its rapid evaporation produces a cool sensation, but be careful not to get it in the eyes” (p. 73).

Another U.S. runner, Matthew Maloney, who established a world record of 2:36:26 in the 1908 New York Evening Journal Christmas Marathon, wrote, “As to what I use when in a Marathon race: I only chew gum. I take no drink at all, but it is well to have a little stimulant on hand, such as beef tea, should it be needed and when I am running I try to get some competent men as handlers on the track, as good ones are needed there” (Martin and Gynn, 1979, p. 45; Sullivan, 1909, p. 57).

The man who reinvigorated interest in ultramarathon running in the 1920s, South African resident Arthur Newton, who won the Comrades Marathon five times and set world records at distances from 48 to 160 km (30 to 100 miles) as well as the world 24-hour running record, had a similar opinion: “You can't lay down a hard and fast rule (about fluid ingestion during exercise, my addition). Even in the warmest English weather, a 26-mile run ought to be manageable with no more than a single drink or, at most, two” (Newton, 1948, p. 15).

From his experiences in the 1928 and 1929 5,510 km (3,422 mile) American Transcontinental races between New York and Los Angeles (Berry, 1990), Newton noticed that the runners focused more on eating than on drinking during the race: “as big a breakfast as they could tuck away immediately before the start” (Newton, 1947). Only after 24 km (15 miles) would they begin to drink “highly sweetened drinks . . . every 4 or 5 miles to keep them going” (pp. 2 and 19).

This advice had not changed by 1957 when Jim Peters, former world-record holder in the 42 km (26 mile) marathon and arguably the greatest marathoner of all time, wrote, “[in the marathon race] there is no need to take any solid food at all and every effort should also be made to do without liquid, as the moment food or drink is taken, the body has to start dealing with its digestion and in so doing some discomfort will invariably be felt” (Peters et al., 1957, p. 114). Indeed a special conference on nutrition and sport held in London before the 1948 London Olympics included no reference to any need to drink during exercise (Abrahams, 1948; Leyton, 1948).

South African Jackie Mekler, who won the 90 km (56 mile) Comrades Marathon on five occasions and set world records at 48 km (30 mile), 64 km (40 mile), and 80 km (50 miles) in 1954, confirmed that Peters spoke for all runners: “In those days it was quite fashionable not to drink, until one absolutely had to. After a race, runners would recount with pride, ‘I only had a drink after 30 or 40 km'” (Noakes, 2003, p. 252) (box 2.1, page 40).

In the 60 years between 1921 and 1981 that Comrades Marathon runners adopted this approach and before drinking stations were provided at increasingly frequent intervals after the mid-1970s, there were no cases of exercise-associated hyponatremia (EAH) or exercise-associated hyponatremia encephalopathy (EAHE) in Comrades runners. Nor is there any recorded evidence that a large number of runners had to be treated for dehydration or heat illness after the Comrades Marathon in those years. Only after the introduction of frequent (every 1.6 km) drinking stations in 1981 did it become increasingly necessary to provide medical care at the finish of that and other marathon and ultramarathon races to treat the growing proportion of collapsed runners seeking medical care for “dehydration” and “heat illness.”

The most likely reason that treatment was necessary was the changing nature of the runners entering marathon and ultramarathon races. Before the running boom that began after 1976, only those who were reasonably trained would ever consider entering those races. But the culture became very different thereafter. The new generation of runners was not told to train more to ensure that they did not suffer harm during those races.

Instead they were advised to drink more.

Soon drinking, especially a sports drink, would be marketed as the universal panacea. A failure to drink properly during competition became the runner's convenient explanation for why he ran less well than expected; certainly in this new era of entitlement it could never be because of something that was under the runner's personal control, specifically that he had simply not trained enough. Doctors, too, would use this reason to rationalize the dramatic increase in the number of athletes seeking medical care at the end of marathon and ultramarathon races and Ironman triathlons. Surely these ill runners had simply drunk too little during these races. If only they could be encouraged to drink more, the problem would surely disappear.

Read more from Waterlogged by Timothy Noakes.

More Excerpts From Waterlogged