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About Our Research Program

Since 2006, the Western States Endurance Run (WSER) has supported basic, applied, clinical and behavioral research associated with the event. The Medical Research program seeks proposals to support research directly applicable, but not limited to, ultramarathon running, running performance, health issues for runners, or using the event as a model for other conditions.

Application Process

Scientific Publications and Projects


Tracy B. Høeg, Kenneth Chmiel, Alexandra E. Warrick, Sandra L. Taylor, and Robert H. Weiss. Ultramarathon Plasma Metabolomics: Phosphatidylcholine Levels Associated with Running Performance. View Full Paper

Tracy Beth Høeg, MD, PhD, Emily Miller Olson, MD, Kira Skaggs, BA, Kristin Sainani, PhD,
Michael Fredericson, MD, Megan Roche, MD, and Emily Kraus, MD. Prevalence of Female and Male Athlete Triad Risk Factors in Ultramarathon Runners. View Full Paper


Dennis Bartholomew and Sheri Poskanzer, MD. Correlation of pre-race carnitine levels with self-reported diet and impact on performance in an 100 mile ultramarathon race.

Emily Kraus, MD, Tracy Beth Hoeg, MD, PhD, Megan Deakins Roche, MD, Kristin Sainani, PhD, Kira Skaggs, BS, Emily Miller, MD, Marko Bodor, MD and Michael Fredricson, MD. Genetic and Blood Biomarker Determinants of Bone Health in Ultramarathoners.


Emily Krause, Michael Fredericson, Tracy Hoeg, Marko Bodor, Mike Weiss. Female Athlete Triad & The Male Equivalent in 100 Mile Ultramarathon Runners – An Investigation of Bone Mineral Density.

Matt Laye. Gut Microbiota of Ultrarunners Prior to and Following a 161 km Ultramarathon Race.


Tracy B. Hoeg, MD, PhD, Kenneth Chmiel, Alexandra E Warrick, Sandra Taylor, and Robert H. Weiss, MD. Metabolomics investigation (Phase II). Ultramarathon plasma metabolomics: phosphatidylcholine levels associated with running performance.

John Diana, MD, Jonathan Brayton, RN, Allison Ganong, MD, and Marko Bodor, MD. Prevalence of anterior labral tears of the hip in ultra-endurance runners.


Hoeg TB, Weiss, R. Ultra-Endurance Running Performance: Initial Correlations from the Metabolomics of Ultramarathon Performance Study (MUmPS). 2016. Summary

Hoeg TB, Corrigan GK, Hoffman MD. An Investigation of Ultramarathon-Associated Visual Impairment. Wilderness and Environmental Medicine. 2016. Article in Press

Hoeg TB, Corrigan GK, Hoffman MK. Alterations in Intraocular Pressure and Corneal Thickness Immediately Following a 161-km Foot Race. 2016. Abstract.


Hoffman MD, Stuempfle KJ, Valentino T. Sodium intake during an ultramarathon does not prevent muscle cramping, dehydration, hyponatremia, or nausea. Sports Med Open 2015;1:39. View Full Paper

Hoffman MD, Weiss RH. Does acute kidney injury from an ultramarathon increase the risk for greater subsequent injury? Clin J Sport Med. 2015 Dec 9. [Epub ahead of print] View Abstract

Hoffman MD. Injuries and health considerations in ultramarathon runners. Phys Med Rehabil Clin N Am. 2016;27(1):203-16. View Abstract

Hoffman MD, Stuempfle KJ. Muscle cramping during a 161-km ultramarathon: Comparison of characteristics of those with and without cramping. Sports Med Open. 2015;1(1):8. Epub 2015 May 21. View Abstract View Full Paper

Hoffman MD, Stuempfle KJ. Does oral buffered sodium supplementation reduce nausea and vomiting during an ultramarathon? Res Sports Med (in press 4/6/15)

Hew-Butler T, Rosner MH, Fowkes-Godek S, Dugas JP, Hoffman MD, Lewis DP, Maughan RJ, Miller KC, Montain SJ, Rehrer NJ, Roberts WO, Rogers IR, Siegel AJ, Stuempfle KJ, Winger JM, Verbalis JG. Statement of the Third International Exercise-Associated Hyponatremia Consensus Development Conference, Carlsbad, California, 2015. Br J Sports Med. 2015;49(22):1432-46. View Full Paper

Joslin J, Hoffman MD, Rogers I, Worthing RM, Ladbrook M, Mularella J. Special considerations in medical screening for participants in remote endurance events. Sports Med. 2015 ;45:1121-31.  View Abstract

Ruby BC, Cuddy JS, Hailes WS, Dumke CL, Slivka DR, Shriver TC, Schoeller DA. Extreme endurance and the metabolic range of sustained activity is uniquely available for every human not just the elite few. Comparative Exerc Physiol. 2015;11:1-7.

Utomi V, Oxborough D, Ashley E, Lord R, Fletcher S, Stembridge M, Shave R, Hoffman MD, Whyte G, Somauroo J, Sharma S, George K. The impact of chronic endurance and resistance training upon the right ventricular phenotype in male athletes. Eur J Appl Physiol. 2015;115:1673-82.  View Abstract

Høeg TB, Corrigan GK, Hoffman MD. An investigation of ultramarathon-associated visual impairment. Wilderness Environ Med. 2015;26:200-4.  View Abstract

Stuempfle KJ, Hoffman MD. Gastrointestinal distress is common during a 161-km ultramarathon. J Sports Sci. 2015;33:1814-21.  View Abstract

Hoffman MD, Stuempfle KJ. Sodium supplementation and exercise-associated hyponatremia during prolonged exercise. Med Sci Sports Exerc. 2015;47:1781-7.  View Abstract

Hoffman MD, Rogers IR, Joslin J, Asplund CA, Roberts WO, Levine BD. Managing collapsed or seriously ill participants of ultra-endurance events in remote environments. Sports Med. 2015;45:201-12.  View Abstract

Lord R, Somauroo J, Stembridge M, Jain N, Hoffman MD, George K, Jones H, Shave R, Haddad F, Ashley E, Oxborough D. The right ventricle following ultra-endurance exercise: insights from novel echocardiography and 12-lead electrocardiography. Eur J Appl Physiol. 2015;115:71-80.  View Abstract

Hew-Butler T, Holexa BT, Fogard K, Stuempfle KJ, Hoffman MD. Comparison of body composition techniques before and after a 161-km ultramarathon using DXA, BIS and BIA. Int J Sports Med. 2015;36:169-74.  View Abstract

McGowan V, Hoffman MD. Characterization of medical care at the 161-km Western States Endurance Run. Wilderness Environ Med. 2015;26:29-35.  View Abstract

Hoffman MD, Stuempfle KJ, Sullivan K, Weiss RH. Exercise-associated hyponatremia with exertional rhabdomyolysis: Importance of proper treatment. Clin Nephrol. 2015;83:235-42. View Abstract


Owen BE, Rogers IR, Hoffman MD, Stuempfle KJ, Lewis D, Fogard K, Verbalis JG, Hew-Butler T. Efficacy of oral versus intravenous hypertonic saline in runners with hyponatremia. J Sci Med Sport. 2014;17:457-62. View Abstract

Utomi V, Oxborough D, Ashley E, Lord R, Fletcher S, Stembridge M, Shave R, Hoffman MD, Whyte G, Somauroo J, Sharma S, George K. Predominance of normal left ventricular geometry in the male ‘athlete’s heart’. Heart. 2014;100:1264-71.  View Abstract

Hoffman MD, Parise CA. Longitudinal assessment of age and experience on performance in 161-km ultramarathons. Int J Sports Physiol Perform. 2014;10:93-8.  View Abstract

Hoffman MD, Stuempfle KJ. Hydration strategies, weight change and performance in a 161-km ultramarathons. Res Sports Med. 2014;22:213-25.  View Abstract

Bennett BL, Hew-Butler T, Hoffman MD, Rogers IR, Rosner MH; Wilderness Medical Society. Wilderness Medical Society practice guidelines for treatment of exercise-associated hyponatremia: 2014 update. Wilderness Environ Med. 2014;25(4 Suppl):S30-42.  View Abstract View Full Paper

Kupchak BR, Kraemer WJ, Hoffman MD, Phinney SD, Volek JS. The impact of an ultramarathon on hormonal and biochemical parameters in men. Wilderness Environ Med. 2014;25:278-88.  View Abstract

Hoffman MD, Pasternak A, Rogers IR, Khodaee M, Hill JC, Townes DA, Scheer BV, Krabak BJ, Basset P, Lipman GS. Medical services at ultra-endurance foot races in remote environments: medical issues and consensus guidelines. Sports Med. 2014;44:1055-69.  View Abstract

Hoffman MD. Pacing by winners of a 161-km mountain ultramarathon. Int J Sports Physiol Perform. 2014;9:1054-6.  View Abstract

Hoffman MD, Krishnan E. Health and exercise-related medical issues among 1,212 ultramarathon runners: Baseline findings from the Ultrarunners Longitudinal TRAcking (ULTRA) Study. PLoS ONE. 2014;9(1): e83867. doi:10.1371/journal.pone.0083867 View Abstract View Full Paper

Kasmer ME, Wren JJ, Hoffman MD. Foot strike pattern and gait changes during a 161-km ultramarathon. J Strength Cond Res. 2014;28:1343-50. View Abstract

Lewis DP, Hoffman MD, Stuempfle KJ, Owen BE, Rogers IR, Verbalis JG, Hew-Butler T. The need for salt: does a relationship exist between cystic fibrosis and exercise-associated hyponatremia? J Strength Cond Res. 2014;28:807-13. View Abstract

Hoffman MD, Chen L, Krishnan E. Body mass index and its correlates in 1,212 ultramarathon runners: Baseline findings from the ULTRA Study. J Phys Act Health. 2014;11:1549-55.  View Abstract


Kupchak BR, Volk BM, Kunces LJ, Kraemer WJ, Hoffman MD, Phinney SD, Volek JS. Alterations in coagulatory and fibrinolytic systems following an ultra-marathon. Eur J Appl Physiol. 2013;113:2705-12. View Abstract

Bennett BL, Hew-Butler T, Hoffman MD, Rogers IR, Rosner MH. In Reply to clinical practice guidelines for treatment of exercise-associated hyponatremia. Wilderness Environ Med. 2013;24:468-71.

Hoffman MD, Krishnan E. Exercise habits of ultramarathon runners: baseline findings from the ULTRA Study. J Strength Cond Res. 2013;27:2939-45. View Abstract View Full Paper

Hew-Butler T, Stuempfle KJ, Hoffman MD. Bone: an acute buffer of plasma sodium during exhaustive exercise? Horm Metab Res. 2013;45:697-700. View Abstract

Bennett BL, Hew-Butler T, Hoffman MD, Rogers IR, Rosner MH. Wilderness Medical Society practice guidelines for treatment of exercise-associated hyponatremia. Wilderness Environ Med. 2013;24:228-40. View Abstract View Full Paper

Hoffman MD, Fogard K, Winger J, Hew-Butler T, Stuempfle KJ. Characteristics of 161-km ultramarathon finishers developing exercise-associated hyponatremia. Res Sports Med. 2013;21:164-75. View Abstract

Winger JM, Hoffman MD, Hew-Butler TD, Stuempfle KJ, Dugas JP, Fogard K, Dugas LR. The effect of physiology and hydration beliefs on race behavior and postrace sodium in 161-km ultramarathon finishers. Int J Sports Physiol Perform. 2013;8:536-41. View Abstract

Hoffman MD, Hew-Butler T, Stuempfle KJ. Exercise-associated hyponatremia and hydration status in 161-km ultramarathoners. Med Sci Sports Exerc. 2013;45:784-91. View Abstract

Hoffman MD, Stuempfle KJ, Fogard K, Hew-Butler T, Winger J, Weiss RH. Urine dipstick analysis for identification of runners susceptible to acute kidney injury following an ultramarathon. J Sports Sci. 2013;31:20-31. View Abstract

Stuempfle KJ, Hoffman MD, Hew-Butler T. Association of gastrointestinal distress in ultramarathoners with race diet. Int J Sport Nutr Exerc Metab. 2013;23:103-9. View Abstract


Millet GY, Hoffman MD, Morin JB. Last word on viewpoint: sacrificing economy to improve running performance–a reality in the ultramarathon? J Appl Physiol. 2012;113:513.

Millet GY, Hoffman MD, Morin JB. Sacrificing economy to improve running performance–a reality in the ultramarathon? J Appl Physiol. 2012;113:507-9.

Hoffman MD, Fogard K. Demographic characteristics of 161-km ultramarathon runners. Res Sports Med. 2012;20:59-69. View Abstract View Full Paper

Hoffman MD, Ingwerson JL, Rogers IR, Stuempfle KJ, Hew-Butler T. Increasing creatine phosphokinase concentration at the 161-km Western States Endurance Run. Wilderness Environ Med. 2012;23:56-60. View Abstract View Full Paper

Hoffman, MD, Stuempfle KJ, Rogers IR, Weschler LB, Hew-Butler T. Hyponatremia in the 2009 161-km Western States Endurance Run. Int J Sports Physiol Perform. 2012;7:6-10. View Abstract


Stuempfle KJ, Hoffman MD, Louise B. Weschler LB, Rogers IR, Hew-Butler T. Race diet of finishers and non-finishers in a 100 mile (161 km) mountain footrace. J Am Col Nutr. 2011;30:529-35. View Abstract

Wegelin JA, Hoffman MD. Variables associated with odds of finishing and finish time in a 161-km ultramarathon. Eur J Appl Physiol. 2011;111:145-53. View Abstract View Full Paper

Hoffman MD, Fogard K. Factors related to successful completion of a 161-km ultramarathon. Int J Sports Physiol Perform. 2011;6:25-37. View Abstract View Full Paper

Rogers IR, Hook G, Stuempfle KJ, Hoffman MD, Hew-Butler T. An intervention study of oral versus intravenous hypertonic saline administration in ultramarathon runners with exercise-associated hyponatremia: a preliminary randomized trial. Clin J Sports Med. 2011;21:200-3. View Abstract

Hew-Butler T, Hoffman MD, Stuempfle KJ, Rogers, IR, Morgenthaler NG, Verbalis JG. Changes in copeptin and bioactive vasopressin in runners with and without hyponatremia. Clin J Sports Med. 2011;21:211-217. View Abstract

Oxborough D, Shave R, Warburton D, Williams K, Oxborough A, Charlesworth S, Foulds H, Hoffman MD, Birch K, George K. Dilatation and dysfunction of the right ventricle immediately following ultra-endurance exercise: exploratory insights from conventional 2-dimensional and speckle tracking echocardiography. Circ Cardiovasc Imaging. 2011;4:253-263. View Abstract

George KP, Warburton DE, Oxborough D, Scott JM, Esch BT, Williams K, Charlesworth S, Foulds H, Oxborough A, Hoffman MD, Shave R. Upper limits of physiological cardiac adaptation in ultramarathon runners. J Am Col Cardiol. 2011;57:754-5. View Abstract

Parise C, Hoffman MD. Influence of temperature and performance level on pacing a 161-km trail ultramarathon. Int J Sports Physiol Perform. 2011;6:243-51. View Abstract View Full Paper


Hoffman MD. Performance trends in 161-km ultramarathons. Int J Sports Med. 2010;31:31-7. View Abstract

Hoffman MD, Lebus DK, Ganong AC, Casazza GA, Van Loan MD. Body composition of 161-km ultramarathoners. Int J Sports Med. 2010;31:106-9. View Abstract

Hoffman MD, Ong JC, Wang G. Historical analysis of participation in 161-km ultramarathons in North America. Int J History Sport. 2010; 27:1877-91. View Abstract View Full Paper

Lebus DK, Casazza GA, Hoffman MD, Van Loan MD. Can changes in body mass and total body water accurately predict hyponatremia following a 161-km running race? Clin J Sports Med. 2010; 20:193-199. View Abstract

Bruso JR, Hoffman MD, Rogers IR, Lee L, Towle G, Hew-Butler T. Rhabdomyolysis and hyponatremia: a cluster of five cases at the 161-km 2009 Western States Run Endurance. Wilderness Environ Med. 2010;21:303-8. View Abstract View Full Paper


Scott JM, Esch BT, Shave R, Warburton DER, Gaze D, George K. Cardiovascular consequences of completing a 160-km ultramarathon. Med Sci Sports Exerc. 2009;41:25–33. View Abstract

Utter AC, Nieman DC, Kang J, Dumke CL, Quindry JC, McAnulty SR, McAnulty LS. Quercetin does not affect rating of perceived exertion in athletes during the Western States endurance run. Res Sports Med. 2009;17:71-83. View Abstract

Hoffman MD, Wegelin J. The Western States 100-Mile Endurance Run: participation and performance trends. Med Sci Sports Exerc. 2009; 41:2191-8. View Abstract


Quindry JC, McAnulty SR, Hudson MB, Hosick P, Dumke C, McAnulty LS, Henson D, Morrow JD, Nieman D. Oral quercetin supplementation and blood oxidative capacity in response to ultramarathon competition. Int J Sport Nutr Exerc Metab. 2008;18:601-16. View Abstract

Hoffman MD. Anthropometric characteristics of ultramarathoners. Int J Sports Med. 2008;29:1-4. View Abstract

Hoffman MD. Ultramarathon trail running comparison of performance-matched men and women. Med Sci Sports Exerc. 2008;40:1681-6. View Abstract

Henson D, Nieman D, Davis JM, Dumke C, Gross S, Murphy A, Carmichael M, Jenkins DP, Quindry J, McAnulty S, McAnulty L, Utter A, Mayer E. Post-160-km race illness rates and decreases in granulocyte respiratory burst and salivary IgA output are not countered by quercetin ingestion. Int J Sports Med. 2008;29:856-63. View Abstract


Dumke CL, Nieman DC, Oley K, Lind RH. Ibuprofen does not affect serum electrolyte concentrations following an ultradistance run. Br J Sports Med. 2007;41:492-6. View Abstract

McAnulty SR, Owens JT, McAnulty LS, Nieman DC, Morrow JD, Dumke CL, Milne GL. Ibuprofen use during extreme exercise: effects on oxidative stress and PGE2. Med Sci Sports Exerc. 2007;39:1075-9. View Abstract

McAnulty S, McAnulty L, Nieman D, Morrow J, Dumke CL, Henson DA. Effect of NSAID on muscle injury and oxidative stress. Int J Sports Med. 2007;28:909-15. View Abstract

Hoffman MD, Lee J, Zhao H, Tsodikov A. Pain perception after running a 100-mile ultramarathon Arch Phys Med Rehabil. 2007;88:1042-8. View Abstract

Nieman DC, Henson DA, Davis JM, Dumke CL, Gross SJ, Jenkins DP, Murphy EA, Carmichael MD, Quindry JC, McAnulty SR, McAnulty LS, Utter AC, Mayer EP. Quercetin ingestion does not alter cytokine changes in athletes competing in the Western States Endurance Run. J Interferon Cytokine Res. 2007;27:1003-11. View Abstract


Nieman DC, Henson DA, Dumke CL, Lind RH, Shooter LR, Gross SJ. Relationship between salivary IgA secretion and upper respiratory tract infection following a 160 km race. J Sports Med Phys Fitness. 2006;46:158-62. View Abstract

Dumke C L, Shooter L, Lind RH, Nieman DC. Indirect calorimetry during ultradistance running-a case report. J Sports Sci Med. 2006;5:692-8.

Publication Summary: Citation refers to study which measured the energy expenditure using a portable metabolic cart of a single subject while running the first 40 miles of the Western States Endurance Run. Based on the findings, it was estimated that the energy cost of running the full 100 miles would be over 13,000 kcals.

Nieman DC, Henson DA, Dumke CL, Oley K, McAnulty SR, Davis JM, Murphy EA, Utter AC, Lind RH, McAnulty LS, Morrow JD. Ibuprofen use, endotoxemia, inflammation, and plasma cytokines during ultramarathon competition. Brain Behav Immun. 2006;20:578-84. View Abstract


Nieman DC, Dumke CL, Henson DA, McAnulty SR, Gross SJ, Lind RH. Muscle damage is linked to cytokine changes following a 160 km running race. Brain Behav Immun. 2005;19:398-403. View Abstract


Nieman DC, Dumke CI, Henson DA, McAnulty SR, McAnulty LS, Lind RH, Morrow JD. Immune and oxidative changes during and following the Western States Endurance Run. Int J Sports Med. 2003; 24: 541-7. View Abstract


Crenshaw AG, Fridén J, Hargens AR, Lang GH, Thornell LE. Increased technetium uptake is not equivalent to muscle necrosis: scintigraphic, morphological and intramuscular pressure analyses of sore muscles after exercise. Acta Physiol Scand. 1993;148:187-98. View Abstract


Crenshaw AG, Fridén J, Thornell LE, Hargens AR. Extreme endurance training: evidence of capillary and mitochondria compartmentalization in human skeletal muscle. Eur J Appl Physiol Occup Physiol. 1991;63(3-4):173-8. View Abstract


Bortz WM II, Angwin P, Mefford IN, Boarder MR, Noyce N, Barchas JD. Catecholamines, dopamine, and endorphin levels during extreme exercise. N Engl J Med. 1981;305:466-7.

Publication Summary: Citation refers to a Letter to the Editor reporting that there was a significant rise above pre-race levels in blood concentrations of norepinephrine, 3,4-dihydroxyphenylacetic acid (DOPAC; a dopamine metabolite) and ß-endorphin while running the 1980 Western States Endurance Run. The authors indicate that the findings suggest an important interaction between the central nervous system and the periphery as a result of high-level physical exertion.

Want to Help Support our Research?

Good research doesn’t come cheap! But we get a lot out of each dollar we put towards research, as you can see from the list of research publications above. If you want to help with our advancement of new knowledge related to ultramarathon running, please consider a tax-deductible donation (WSER Tax ID #094-2902794).

We thank the following past corporate and individual sponsors of our research program.

Marcia Adams
Maxine Angell
Donald & Laverne Angotti
William A Bacigalupi
Rick Beller, MD
Debbie & Dan Benzon
Michel Blom
Lola Braccini
Robert Brandon, PT
Nancy Brennan
Dave & Laurie Buurma
Alfred J Cali
Robert Cauthorn
J Celio
Joan Clark
William Coffield
David Coggiola
Jonathan Cohen, MD
Karen Colwell
Mary Craig
Nancy Davies
Ramona J Decker
Joanne Depuy
Steven J Diamond
John & Theresa Diana
Richard Dresden
James Edwards, MD
Jerry Ellis
Joanne Evers
Eric Ewig, PT
Billy Ewing
RC Faria
Dick & Jane Finaly
Gary Forbes
Harold Fox
Angela Franceschi
Gary Garaventa
Kimberly Gaylord
William German
Nina Gibson
Virginia & Barbara Glagola
Frank Grange
Brittany L Goss, DO, Inc.
Barry Hamilton
Lee Hamilton, MD
Joan Hatton
Sherry A Hanson
Ed & Marie Henderson
David A Hill
Lenore Hirsch
Karl & Erika Hoagland
Clinton Holdsworth
Lorraine Hughes
Valerie Hunt
Elzbieta Hyde
Dinah Cross James
Marie Kennelly
Mary Lou King
Joseph Knoblauch
Clifford Knuckles
Jason Koop
Bill Kroplin
Annemarie Lando
Doug Latimer
Lois Lourie
James Luce
Lella P Lyons
Leo Maionchi
Sharon Marangoni
George Marcy
Lou & Kathy Martin
Brian McGeeney
Kevin McGeeney
John Medinger
Sandra Myers
Jenny & Tom Obermeier
Joanne S O’Callaghan
Kimberly Opitz, PA-C
William Orr
Keith Pieper
Jesse & Brenda Pittore
Donna Prewoznik
Ethel Ramos
Narendra Rocherolle
Tom & Gail Rossi
Rossi Family Foundation
Dario Sattui
Charles Savage
Loueen Schreiner
Fred & Marjorie Schweizer
Michael Shifflett, MD
Gail & Paul Silvestri
Dennis Sisto
Robert Snyder
Karsten Solheim
Marilyn Soulsburg
Jose Suarez
Paul Sweigert, MD
Charles Taylor
Robert W Theisen
Rue Tikker, DPM
Bo & Cindy Titchenal
John Trefethen
Kenneth Tubman
Jay Watson
Mary Wilson
MaryEllen & Jim Wilson
Mark Worley
Castello Di Amoroso
Edge Physical Therapy
Lodi Health
Napa Valley Orthopaedic Medical Group, Inc.
Napa Valley Research Foundation
Napa Valley Physical Therapy
Razi Family Winery
Sierra Nevada Hospital
Sutter Health
Think Ice Cream
V. Sattui Winery
X23 and Me