The Science of Badwater

2008 Research

Measures of water turnover, body temperature, activity and heat strain during the Badwater ultramarathon

The Montana Center for Work Physiology and Exercise Metabolism (Montana WPEM) is conducting an exciting research project at the 2008 Badwater Ultramarathon. You have been there done that as far as ultras go. However, here is a chance to put some physiological bragging rights behind your 2008 race. Just how much water does the human body turn over in 135 miles? How does your hydration strategy stack up and protect you from overheating? Have you ever seen a mobile physiological lab in the form of a Airstream trailer? If you want to know - we want you in our project. We have done Western States, now we want to see how Badwater stacks up as we encroach towards the human ceiling for energy expenditure and hydration demands.

We are limited to studying 12 racers. Also, we are only able to use racers from the western part of the U.S. for reasons mentioned in the attached brochure. If you are interested, please contact Brent Ruby at the email below and reference the attached Pdf document.

This proposed research would evaluate the effects of environmental stress on measures of hydration, total body water turnover, core temperature, and heat shock protein response during the 2008 Badwater Ultramarathon.

Water turnover offers a dynamic measure of hydration demands by quantifying the magnitude of total body water loss coupled with partial or complete replacement over a given period of time. The unique measure of water turnover is not simply a measure of how much water is consumed and how much water is lost, it is an all inclusive measure of water flux through the human system. A 75 kg reference man contains about 45 L of water (~60% of total body weight). During some of our previous field investigations with wildland fire fighters, Air Force Combat controllers, and Ironman athletes our laboratory has demonstrated 12-24hr water turnover values in the range of 6-18 L (up to 40% of total water volume). Even with this data we have no indication that these activities have stressed the human hydration system to its full capacity. Further research, as proposed here, is needed to determine the human ceiling for water turnover in order to further characterize the hydration needs for extended work in hostile environments.

Because these types of events may capture the human ceiling for extended muscle work in the heat, these data will provide valuable insight towards the cellular protection associated with a change in heat shock protein response patterns. Moreover, this approach will assist in determining human factors that limit or sustain performance during an extended period of activity. The data collection we are planning for Badwater 2008 will extend our past research because of the unique environment and duration of the event.

Brent C. Ruby, Ph.D., FACSM
Director, Montana Center for Work Physiology and Exercise Metabolism (Montana WPEM)
Email: brent.ruby"at"

2007 Research

Hormonal Control of Hydration and Sodium Balance during the Badwater Ultramarathon

Researchers: Jeff Lynn, Ph.D. Slippery Rock University, Lisa S. Bliss MD, and Jim Roberts, Ph.D. Edinboro University

At the 2007 Badwater Ultramarathon we conducted a follow-up investigation to the research we completed at the 2006 race. In 2006, we studied 4 runners and found that their body weights remained stable (<2% change) and their serum sodium concentrations remained within the normal range. However, we observed marked decreases in sweat sodium concentration and increases in urine sodium levels as the race progressed. Therefore, the principle aim of the study at the 2007 race was to gain a better understanding of how hormones that control fluid balance and sodium fluctuate during the race.

We recruited 12 race participants (8 men, 4 women) to take part in a study investigating the hormonal control of hydration and sodium balance. We asked the runners and their crews to record all food, beverage, and supplement intake to the best of their ability throughout the race so that we could assess fluid and sodium intake. We measured body weight, serum sodium, sweat sodium, urine sodium, urine volume, and urine specific gravity. We also measured the following hormones in the blood, which are known to influence hydration and sodium balance in the body: Arginine Vasopressin (AVP), Aldosterone, and Atrial Natriuretic Peptide (ANP). Data were collected at 3 times: 1) before the start, 2) Stovepipe Wells (SPW), and 3) the finish line.

Eleven of the study participants finished the race. We were unable to gather complete data in all 11 finishers due to challenges implicit in this type of field research. Data analyses are ongoing. Based on the data collected and analyzed, we can report the following observations:

  • Fluid and sodium intake varied greatly between participants.
  • Body weights tended to decrease between the start and SPW, but then trended slightly upward from that point to the finish. The changes in weight were all 5% or less.
  • Serum sodium concentrations were normal for all participants at the start line, but tended to decrease between the start and SPW. At that point, 2 runners (both women) were slightly hyponatremic (Na,130-134). There was no trend in serum sodium concentrations from SPW to the finish, but 3 runners were slightly hyponatremic at the finish line (all 3 were women). None of the participants needed medical treatment.
  • Sweat sodium concentration decreased in each participant as the race progressed.
  • No consistent trend was observed in urine sodium concentrations as the race progressed.
  • Arginine Vasopressin (AVP) appeared to increase as body weight decreased and vice-versa (as expected).
  • Neither Aldosterone nor ANP levels were consistently what would be expected considering the hydration status of the runners at the time they were measured. We are continuing to investigate this finding.

The studies over the past 2 years demonstrate that runners maintain near normal hydration and serum sodium levels across a great range of sodium and fluid intakes.  Although it is still not clear how the hydration hormones are acting during the extreme challenge of running the Badwater Ultramarathon, we have some interesting data that we will continue to analyze and gain a better understanding of how the body responds to survive during this remarkable challenge. The next step is to combine what we’ve learned from the Badwater Ultramarathon studies in 2006 and 2007 and publish our findings.

Watch a short video regarding this research.

2006 Research

Sodium Balance Study Research Results: Badwater Ultramarathon 2006

Researchers: Jeff Lynn, PhD, Lisa S. Bliss, MD, Joe Chorley, MD

At the Badwater Ultramarathon in 2006, we conducted a descriptive study investigating sodium balance. We recruited four race participants, 2 men and 2 women, and measured body weight, serum sodium concentration, urine sodium concentration, sweat sodium concentration, and urine specific gravity at 4 collection points: 1) before the race, 2) at Furnace Creek, 3) at Stove Pipe Wells, and 4) at the finish line. The subjects  crews collected and recorded additional information to the best of their ability, including sodium intake from food, supplements, and electrolyte drinks, as well as amount of urine output.

Sweat patches were applied at each collection point and removed 20 minutes later and stored for later analysis at a hospital lab. Serum sodium was analyzed immediately with iSTAT point of care analyzers (Abbott Labs). Urine was collected in urinals and analyzed by the researchers at each collection point for specific gravity (which assesses hydration status) and urine sodium concentration. Weight was taken with calibrated scales.

All four runners completed the race and none required medical attention at any point. Although we were unable to gather complete data for all runners due to the challenges implicit in a field study of this type, we observed some trends in the data that we were able to collect. The trends were as follows:

  • Those who reported the most heat acclimatization training prior to the race had a lower sweat sodium concentration at the start
  • Sweat sodium concentration decreased in each subject as the race progressed.
  • Urine sodium concentration increased in each subject as the race progressed.
  • Serum sodium concentration remained normal in all subjects throughout the race.
  • Weight changes during the race fluctuated between 0 and 2% for each subject.

Other observations:

  • Sodium intake between subjects varied tremendously.
  • Sodium balance homeostasis was maintained despite extraordinarily challenging conditions and bodily stress.

Future Plans:

  • We will be submitting these data for publication.
  • We will be conducting additional studies to investigate the physiological mechanisms responsible for these trends.

2005 Research

Study on Fluids and Electrolyte Balance: “Hyponatremia in Ultramarathoners”

By Joseph N. Chorley, M.D., Principal Investigator, Lisa S. Bliss, M.D., Medical Director and 2004 Badwater Finisher, and Jeffrey S. Lynn, PhD.

Many 2005 entrants were invited to participate in a research study that will help to define the fluid and electrolyte balance of extraordinary athletes in extreme environments like the Badwater Ultramarathon. The researchers were especially interested in studying hyponatremia (low blood sodium). Two research groups were utilized for this study:

  • Group 1: Questionnaire and blood and urine measurements BEFORE and AFTER the race only
  • Group 2: Same as group 1, but also have a questionnaire and blood draw at Stove Pipe Wells (42 mi) and Panamint Springs (75 mi)

The crews for participants in both groups were asked to record information about their runners' food and fluid intake during the race.

Initial results were presented by Dr. Joe Chorley at the Endurance Special Interest Group at the ACSM Conference in June 2006.

View a short video interview with Dr. Lisa Bliss regarding this study.

“Myocardial Stress During and After Ultra-Endurance Running in Extreme Heat”

Leithäuser Renate M1, Doppelmayr Hildegard2, Doppelmayr Michael3, Finkernagel Holger4, von Duvillard Serge P5, Roth Heinz J6, Beneke Ralph1.

Download one-page PDF

A research study focusing on heart rate responses during ultra-endurance events took place during the 2005 race.

Download one-page PDF

2004 Research

“Red Blood Cell or Total Protein Based Calculation of Plasma Volume Changes Under Marathon Conditions in Extreme Heat”

By Von Duvillard Serge P, Branks Dale, Doppelmayr Hildegard, Doppelmayr Michael, Finkernagel Holger, Leithäuser Renate M, Roth Heinz J, Beneke Ralph

“Glykämische und kardiovaskuläre Parameter bei Typ-1-Diabetes im Vergleich zu stoffwechselgesunden Sportlern unter den Bedingungen eines Extrem-Ultramarathonlaufes”

H.Finkernagel1, R. Beneke5, M. Doppelmayr4, M. Herrmann6,  A.Thomas2, J.Pumprla3, R.Leithaeuser7

2003 Research

“Within the Dreams, Reality, and Hallucinations of Ultra-Marathon Runners”

By Andrew J. Mojica, University of Texas, El Paso, 2003.

“The hallucinations induced by ultra-marathons can give the sensation of reality, depending how many sensory modalities are affected. (Weiss & Heckers, 1999; Izumi, Terao, Ishino, & Nakamura, 2002) The degree of the intensity of the hallucination is affected not only through certain biological conditions of hallucinations, but also through a person’s cognitive perspective (Glicksohn, 1990; Klemperer, 1992). The cognitive aspect of perception plays an important part in helping a person to distinguish the normal from the abnormal. The presence of fatigue, monotony, or intense emotions, can obstruct these cognitive mechanisms that are normally used to help filter sensory information, creating an even more realistic hallucination (Beyerstein, 1996).”

Read full paper.

2002 Research

“Changes in Cognitive Performance During a 216 km Extreme Endurance Footrace: A Descriptive and Perspective Study.”

By Doppelmayr, Michael M. Finkernagel, Holger. Doppelmayr, Hildegard I.

Perceptual & Motor Skills. 100(2):473-87, 2005 Apr. (You may request the full eight-page paper as a PDF file via email from us.)

Abstract: Two subjects participated in a 216 km ultramarathon with outside temperatures above 50 degrees C while several physiological and psychological parameters (cognitive performance assessed by a mental calculation task and an attentional task, subjective bodily experience, and lactate level) were evaluated throughout the race. Severe stress from dehydration, sleep deprivation, and total physical exhaustion are combined in a unique manner, allowing evaluation of their effects in a range far outside that obtainable in a laboratory setting. During the race the subjects answered a questionnaire about their actual bodily experiences, underwent 8 medical examinations, and performed two cognitive tests approximately every 35 kilometers. Analysis showed cognitive performance did not decrease steadily in a simple and gradual way but reached a peak in the morning of Day 2 after a short sleeping period and then decreased. In the early morning of Day 3, in general cognitive performance exhibited the worst results but increased differentially between the subjects again in the last test 1 km before the finish line.