The Limits of Human Endurance: What is the Greatest Endurance Performance of All Time? Which Factors Regulate Performance at Extreme Altitude?
Part of the
Advances in Experimental Medicine and Biology
book series (AEMB, volume 618)
Humans evolved as an athletic species able to run in the midday heat, to throw with exquisite accuracy and to strike powerfully despite relatively weak upper arms compared to those of the great apes. The true extent to which humans could run long distances was first tested in a unique series of 6-day foot races contested between 1874 and 1888 by professional athletes from England and the United States. These athletes typically would have expended approximately 60 000 kcal (24.12 MJ) of energy during these races. The discovery of the bicycle soon caused the replacement of these races by 6-day cycling races which, in turn, led to the modern day Tour de France, the cycling race across America (RaAM) and two running races across the width of the United States in 1928 and 1929. The total energy expenditures during these different events can be estimated at approximately 168 000, 180 000 and 340 000 kcal respectively.
But, in terms of the total energy expenditure, all these performances pale somewhat when compared to that of Robert Falcon Scott’s Polar party during the 1911/12 British Antarctic Expedition. For most of 159 consecutive days, Scott’s team man-hauled for 10 hours a day to the South Pole and back covering a distance of 2 500 km. Their predicted total energy expenditure per individual would have been about 1 million kcal, making theirs, by some margin, the greatest sustained endurance athletic performance of all time. Interestingly, the dogs that provided the pulling power for Norwegian Roald Amundsen’s team that was the first to reach the South Pole, 35 days before Scott’s party, would have expended about 500 000 kcal in their 97 day trip, making theirs the greatest animal “sporting” performance on record. By contrast, mountain climbers expend only approximately4 000 kcal/day when climbing at extreme altitudes (above 4 000 m). This relatively low rate of energy expenditure results from the low exercise intensities that can be sustained at extreme altitude. Here I argue that this slow rate of energy expenditure is caused, not by either myocardial or skeletal muscle hypoxia as is usually argued, but is more likely the result of a process integrated HYPoXia and tHE CiRCulation Chapter 0 centrally in the brain, the function of which is to protect the body from harm. At extreme altitude the organ at greatest risk is the brain which must be protected from the catastrophic consequences of profound hypoxia. A key feature of this control is that it acts “in anticipation” specifically to insure that a catastrophic biological failure does not occur. The evidence for this interpretation is presented.
Key Wordsenergy expenditure heart central governor evolution hunting
Amann M, Eldridge MW, Lovering AT, Stickland MK, Pegelow DF and Dempsey JA. Arterial oxygenation influences central motor output and exercise performance via effects on peripheral locomotor muscle fatigue in humans. J Physiol
575:937-952, 2006.Google Scholar
Bender PR, Groves BM, McCullough RE, McCullough RG, Huang SY, Hamilton AJ, Wagner PD, Cymerman A and Reeves JT. Oxygen transport to exercising leg in chronic hypoxia. J Appl Physiol
65:2592-2597, 1988.PubMedGoogle Scholar
Berry H. From L.A. to New York, from New York to L.A.
Chorley: H. Berry, 1990.Google Scholar
Bigland-Ritchie B and Vollestadt N. Hypoxia and fatigue: How are they related? In: Hypoxia: the tolerable limits.
, edited by JR Sutton, CS Houston and G Coates. Indianapolis IL: Benchmark, 1988, p. 315-325.Google Scholar
Bramble DM and Lieberman DE. Endurance running and the evolution of Homo. Nature
432:345-352, 2004.CrossRefPubMedGoogle Scholar
Calbet JA, Boushel R, Radegran G, Sondergaard H, Wagner PD and Saltin B. Determinants of maximal oxygen uptake in severe acute hypoxia. Am.J Physiol
284:R291-R303, 2003.PubMedGoogle Scholar
Calbet JA, Boushel R, Radegran G, Sondergaard H, Wagner PD and Saltin B. Why is VO2 max after altitude acclimatization still reduced despite normalization of arterial O2 content? Am.J Physiol Regul.Integr.Comp Physiol
284:R304-R316, 2003.PubMedGoogle Scholar
Cherry-Garrard A. The worst journey in the world
. New York: Carroll and Graf, 1989.Google Scholar
Cymerman A, Reeves JT, Sutton JR, Rock PB, Groves BM, Malconian MK, Young PM, Wagner PD and Houston CS. Operation Everest II: maximal oxygen uptake at extreme altitude. J Appl Physiol
66:2446-2453, 1989.CrossRefPubMedGoogle Scholar
Diamond J. Evolutionary design of intestinal nutrient absorption enough but not too much. News in Physiological Science
6:92-96, 1991.Google Scholar
Foster C and Foster D. Speaking with earth and sky
. Cape Town: David Phillips Publishers, 2005.Google Scholar
Fowkes Godek S, Bartolozzi AR and Godek JJ. Sweat rate and fluid turnover in American football players compared with runners in a hot and humid environment. Br J Sports Med
39:205-211, 2005.CrossRefPubMedGoogle Scholar
Fulco CS, Lewis SF, Frykman PN, Boushel R, Smith S, Harman EA, Cymerman A and Pandolf KB. Muscle fatigue and exhaustion during dynamic leg exercise in normoxia and hypobaric hypoxia. J Appl Physiol
81:1891-1900, 1996.PubMedGoogle Scholar
Gandevia SC. Spinal and supraspinal factors in human muscle fatigue. Physiol Rev
81:1725-1789, 2001.PubMedGoogle Scholar
Garner SH, Sutton JR, Burse RL, McComas AJ, Cymerman A and Houston CS. Operation Everest II: neuromuscular performance under conditions of extreme simulated altitude. J Appl Physiol
68:1167-1172, 1990.PubMedGoogle Scholar
Godek SF, Bartolozzi AR, Burkholder R, Sugarman E and Dorshimer G. Core temperature and percentage of dehydration in professional football linemen and backs during preseason practices. J Athl.Train.
41:8-14, 2006.PubMedGoogle Scholar
Gordon B and Baker JC. Observations on the apparent adaptability of the body to infections, unusual hardships, changing environment and prolonged strenuous exertion. Am.J Med.Sci.
178:1-8, 1929.CrossRefGoogle Scholar
Green HJ, Sutton JR, Cymerman A, Young PM and Houston CS. Operation Everest II: adaptations in human skeletal muscle. J Appl Physiol
66:2454-2461, 1989.PubMedGoogle Scholar
Groves BM, Reeves JT, Sutton JR, Wagner PD, Cymerman A, Malconian MK, Rock PB, Young PM and Houston CS. Operation Everest II: elevated high-altitude pulmonary resistance unresponsive to oxygen. J Appl Physiol
63:521-530, 1987.PubMedGoogle Scholar
Heacox K. Shackleton: The Antarctic Challenge
. Washington, D.C.: National Geographic, 1999.Google Scholar
Heinrich B. Racing the antelope
. New York: Harper Collins Publishers Inc., 2001.Google Scholar
Hill AV, Long CNH and Lupton H. Muscular exercise, lactic acid and the supply and utilisation of oxygen - parts VII-VIII. Proc.Royal Soc.
97:155-176, 1925.Google Scholar
Huntford R. The last place on earth
. London: Pan Books Ltd, 1981.Google Scholar
Jeukendrup AE. High Performance Cycling
. Champaign: Human Kinetics Publishers, 2002.Google Scholar
Kayser B, Narici M, Binzoni T, Grassi B and Cerretelli P. Fatigue and exhaustion in chronic hypobaric hypoxia: influence of exercising muscle mass. J Appl Physiol
76:634-640, 1994.PubMedGoogle Scholar
Knechtle B, Enggist A and Jehle T. Energy turnover at the Race Across America (RAAM) - a case report. Int.J Sports Med
26:499-503, 2005.Google Scholar
Liebenberg L. The art of tracking: The origin of science
. Claremont, South Africa: David Philip Publishers (Pty) Ltd, 1990.Google Scholar
Lucia A, Hoyos J, Santalla A, Earnest C and Chicharro JL. Tour de France versus Vuelta a Espana: which is harder? Med.Sci.Sports.Exec.
35:872-878, 2003.CrossRefGoogle Scholar
Malconian M, Rock P, Hultgren H, Donner H, Cymerman A, Groves B, Reeves J, Alexander J, Sutton J, Nitta M and . The electrocardiogram at rest and exercise during a simulated ascent of Mt. Everest (Operation Everest II). Am J Cardiol.
65:1475-1480, 1990.CrossRefPubMedGoogle Scholar
Messner R. Everest: Expedition to the Ultimate
. London: Kaye & Ward, 1979.Google Scholar
Noakes TD. Lore of Running
. Human Kinetics Publishers, Champaign, IL, 2003.Google Scholar
Noakes TD. Challenging beliefs: ex Africa semper aliquid novi: 1996 J.B. Wolffe Memorial Lecture. Med.Sci.Sports Exerc.
29:571-590, 1997.PubMedGoogle Scholar
Noakes TD. Maximal oxygen uptake: “classical” versus “contemporary” viewpoints: a rebuttal. Med.Sci.Sports Exerc.
30:1381-1398, 1998.CrossRefPubMedGoogle Scholar
Noakes TD. Physiological models to understand exercise fatigue and the adaptations that predict or enhance athletic performance. Scand.J.Med.Sci.Sports
10:123-145, 2000.CrossRefPubMedGoogle Scholar
Noakes TD. Should we allow performance-enhancing drugs in sport? A rebuttal to the article by Savulescu and colleagues. Int J Sports Sci & Coaching
1:289-316, 2006.Google Scholar
Noakes TD. The limits of endurance exercise. Basic Res Cardiol.
101: 408-417, 2006.CrossRefPubMedGoogle Scholar
Noakes TD. The Central Governor Model of exercise regulation applied to the marathon. Sports Med.
37:(in press), 2007.Google Scholar
Noakes TD, Calbet JA, Boushel R, Sondergaard H, Radegran G, Wagner PD and Saltin B. Central regulation of skeletal muscle recruitment explains the reduced maximal cardiac output during exercise in hypoxia. American Journal of Physiology-
Regulatory Integrative and Comparative Physiology
287:R996-R999, 2004.Google Scholar
Noakes TD, Peltonen JE and Rusko HK. Evidence that a central governor regulates exercise performance during acute hypoxia and hyperoxia. J.Exp.Biol.
204:3225- 3234, 2001.PubMedGoogle Scholar
Noakes TD and St Clair Gibson A. Logical limitations to the “catastrophe” models of fatigue during exercise in humans. Br J Sports Med
38:648-649, 2004.CrossRefPubMedGoogle Scholar
Noakes TD, St Clair Gibson A and Lambert EV. From catastrophe to complexity: a novel model of integrative central neural regulation of effort and fatigue during exercise in humans. Br.J.Sports Med.
38:511-514, 2004.CrossRefPubMedGoogle Scholar
Noakes TD, St Clair Gibson A and Lambert EV. From catastrophe to complexity: a novel model of integrative central neural regulation of effort and fatigue during exercise in humans: summary and conclusions. British Journal of Sports Medicine
39:120-124, 2005.CrossRefPubMedGoogle Scholar
Pugh LG. The logistics of the polar journeys of Scott, Shackleton and Amundsen. Proc.R Soc Med
65:42-47, 1972.PubMedGoogle Scholar
Reeves JT, Groves BM, Sutton JR, Wagner PD, Cymerman A, Malconian MK, Rock PB, Young PM and Houston CS. Operation Everest II: preservation of cardiac function at extreme altitude. J Appl Physiol
63:531-539, 1987.PubMedGoogle Scholar
Robach P, Tomsen JJ, Mollard P, Calbet J, Boushel R and Lundby C. Recombinant human erythropoietin treatment increases maximal oxygen uptake at moderate altitude. High Altitude Medicine & Biology
7:342-343, 2006.Google Scholar
Rontoyannis GP, Skoulis T and Pavlou KN. Energy balance in ultramarathon running. Am J Clin Nutr.
49:976-979, 1989.Google Scholar
Saris WH, Erp-Baart MA, Brouns F, Westerterp KR and ten Hoor F. Study on food intake and energy expenditure during extreme sustained exercise: the Tour de France. Int.J Sports Med
10 Suppl 1:S26-S31, 1989.CrossRefGoogle Scholar
Shackleton E. South: Journals of His Last Expedition to Antarctica
. Old Saybrook, CT: Konecky & Knoecky, 1999.Google Scholar
Shackleton E. The heart of the Antarctic
. New York, NY: Carroll and Graf Publishers Inc., 1999.Google Scholar
Solomon S. The Coldest March
. New Haven: Yale University Press, 2001.Google Scholar
St Clair Gibson A and Noakes TD. Evidence for complex system integration and dynamic neural regulation of skeletal muscle recruitment during exercise in humans. Br.J.Sports Med.
38:797-806, 2004.CrossRefPubMedGoogle Scholar
Stroud M. The nutritional demands of very prolonged exercise in man. Proc.Nutr.Soc.
57:55-61, 1998.PubMedGoogle Scholar
Stroud MA. Nutrition and energy balance on the ‘Footsteps of Scott’ expedition 1984-Hum Nutr.Appl.Nutr.
41:426-433, 1987. 5Google Scholar
Stroud MA, Coward WA and Sawyer MB. Measurements of energy expenditure using isotope-labeled water (2H2(18)O) during an Arctic expedition. Eur.J Appl.Physiol
67:375-379, 1993.CrossRefPubMedGoogle Scholar
Stroud MA, Jackson AA and Waterlow JC. Protein turnover rates of two human subjects during an unassisted crossing of Antarctica. Br J Nutr.
76:165-174, 1996.CrossRefPubMedGoogle Scholar
Stroud MA, Ritz P, Coward WA, Sawyer MB, Constantin-Teodosiu D, Greenhaff PL and Macdonald IA. Energy expenditure using isotope-labeled water (2H218O), exercise performance, skeletal muscle enzyme activities and plasma biochemical parameters in humans during 95 days of endurance exercise with inadequate energy intake. Eur.J Appl.Physiol Occup.Physiol
76:243-252, 1997.CrossRefPubMedGoogle Scholar
Sutton JR, Reeves JT, Wagner PD, Groves BM, Cymerman A, Malconian MK, Rock PB, Young PM, Walter SD and Houston CS. Operation Everest II: oxygen transport during exercise at extreme simulated altitude. J Appl Physiol
64:1309-1321, 1988.PubMedGoogle Scholar
Tucker R, Marle T, Lambert EV and Noakes TD. The rate of heat storage mediates an anticipatory reduction in exercise intensity during cycling at a fixed rating of perceived exertion. J.Physiol.
574:905-915, 2006.CrossRefPubMedGoogle Scholar
Tucker R, Rauch L, Harley YX and Noakes TD. Impaired exercise performance in the heat is associated with an anticipatory reduction in skeletal muscle recruitment. Pflugers Arch.
448:422-430, 2004.CrossRefPubMedGoogle Scholar
Wagner PD. Reduced maximal cardiac output at altitude–mechanisms and significance. Respir.Physiol
120:1-11, 2000.CrossRefPubMedGoogle Scholar
Wagner PD, Sutton JR, Reeves JT, Cymerman A, Groves BM and Malconian MK. Operation Everest II: pulmonary gas exchange during a simulated ascent of Mt. Everest. J Appl Physiol
63:2348-2359, 1987.PubMedGoogle Scholar
West JB. Lactate during exercise at extreme altitude. Fed.Proc
45:2953-2957, 1986.PubMedGoogle Scholar
Westerterp KR, Kayser B, Brouns F, Herry JP and Saris WH. Energy expenditure climbing Mt. Everest. J Appl Physiol
73:1815-1819, 1992.PubMedGoogle Scholar
Woodland L. The crooked path to victory
. San Francisco: Cycle Publishing, 2003.Google Scholar
Young AJ, Sawka MN, Muza SR, Boushel R, Lyons T, Rock PB, Freund BJ, Waters R, Cymerman A, Pandolf KB and Valeri CR. Effects of erythrocyte infusion on VO2max at high altitude. J Appl Physiol
81:252-259, 1996Google Scholar
© Springer Science+Business Media, LLC 2007