The Sports Gene: Inside the Science of Extraordinary Athletic Performance

by David Epstein

  Schechter, Bruce. “How Much Higher? How Much Faster?” In: Editors of Scientific American, eds. Building the Elite Athlete. Scientific American, 2007.

  115 The quote regarding the perfect form of man appears here:

  Sargent, D. A. (1887). “The Physical Characteristics of the Athlete.” Scribner’s Magazine, 2(5):558.

  116 Norton and Olds have written extensively on the changing bodies in the elite athlete pool. Here are two of the best compilation papers, from which many of the sport-specific examples in this chapter were drawn:

  Norton, Kevin, and Tim Olds (2001). “Morphological Evolution of Athletes Over the 20th Century: Causes and Consequences.” Sports Medicine, 31(11):763–83.

  Olds, Timothy. “Chapter 9: Body Composition and Sports Performance.” In: Ronald J. Maughan, ed. The Olympic Textbook of Science in Sport, Blackwell Publishing, 2009.

  117 Very tall women are 191 times more likely to make an Olympic final than very small women:

  Khosla, T., and V. C. McBroom (1988). “Age, Height and Weight of Female Olympic Finalists.” British Journal of Sports Medicine, 19:96–99.

  119 Norton and Olds coedited the textbook Anthropometrica (UNSW Press, 2004), the definitive introduction to the measurement of body types in sports. Chapter 11, “Anthropometry and Sports Performance,” is a treasure trove of information, from the rapid change in the height of high jumpers after the introduction of the Fosbury flop, to graphs showing how the bodies of world record holders vary according to the distance they run.

  119 Heat dissipation and body size of runners:

  O’Connor, Helen, Tim Olds, and Ronald J. Maughan (2007). “Physique and Performance for Track and Field Events.” Journal of Sports Sciences, 25(S2):S49–60.

  120 The effect of core temperature on effort (and the impact of amphetamines):

  Roelands, Bart, et al. (2008). “Acute Norepinephrine Reuptake Inhibition Decreases Performance in Normal and High Ambient Temperature.” Journal of Applied Physiology, 105:206–12.

  Tucker, Ross (2009). “The Anticipatory Regulation of Performance: The Physiological Basis for Pacing Strategies and the Development of a Perception-Based Model for Exercise Performance.” British Journal of Sports Medicine, 43:392–400.

  120 Heat dissipation discussion specifically with respect to Paula Radcliffe:

  Schwellnus, Martin P., ed. The Olympic Textbook of Medicine in Sport. Wiley, 2008, p. 463.

  120 The famous 1968 Mexico City Olympics study of body types:

  de Garay, Alfonso L., Louise Levine, and J. E. Lindsay Carter, eds. Genetic and Anthropological Studies of Olympic Athletes. Academic Press, 1974.

  121 Michael Phelps’s short inseam:

  McMullen, Paul. “Measure of a Swimmer: From Flipper Feet to a Long Trunk, Phelps Represents a One-Man Body Shop of What a Swimmer Should Be.” Baltimore Sun, March 9, 2004.

  122 Salary gap between average workers and pro athletes (updated using figures from the U.S. Census Bureau):

  Olds, Timothy. “Chapter 9: Body Composition and Sports Performance.” In: Ronald J. Maughan, ed. The Olympic Textbook of Science in Sport. Blackwell Publishing, 2009.

  122 The GIANT Consortium study:

  Willer, C. J., et al. (2009). “Six New Loci Associated with Body Mass Index Highlight a Neuronal Influence on Body Weight Regulation.” Nature Genetics, 41(1):25–34.

  123 Researchers in the United States and Finland have found that a high proportion of fast-twitch muscle fibers decreases fat burning and increases blood pressure and risk of heart disease:

  Hernelahti, Miika, et al. (2008). “Muscle Fiber-Type Distribution as a Predictor of Blood Pressure: A 19-Year Follow-Up Study.” Hypertension, 45(5):1019–23.

  Kujala, Urho M., and Heikki O. Tikkanen (2001). “Disease-Specific Mortality Among Elite Athletes.” JAMA, 285(1):44.

  Tanner, Charles J., et al. (2002). “Muscle Fiber Type Is Associated with Obesity and Weight Loss.” American Journal of Physiology—Endocrinology and Metabolism, 282:E1191–96.

  124 Francis Holway graciously shared spreadsheets of his data on the body measurements of athletes.

  124 Cowgill on innate skeletal differences:

  Cowgill, L. W. (2010). “The Ontogeny of Holocene and Late Pleistocene Human Postcranial Strength.” American Journal of Physical Anthropolgy, 141(1):16–37.

  126 Tanner’s quote comes from:

  Tanner, J. M. Fetus into Man: Physical Growth from Conception to Maturity (revised and enlarged edition). Harvard University Press, 1990.

  8

  The Vitruvian NBA Player

  129 Dennis Rodman confirmed his rapid height growth in an interview, but his book is the most colorful account and provided his quotes:

  Rodman, Dennis. Bad as I Wanna Be. Dell, 1997.

  130 Michael Jordan notes that he began dunking as a 5'8" freshman in the video Come Fly with Me (Fox/NBA), and his brother’s athleticism and diminutive stature is often recounted, perhaps most eloquently in chapter 2 of David Halberstam’s Playing for Keeps: Michael Jordan and the World He Made. Three Rivers Press, 2000.

  131 Gene mixing may be contributing to widespread increase in height:

  Malina, Robert M. (1979). “Secular Changes in Size and Maturity: Causes and Effects.” Monographs of the Society for Research in Child Development, 44(3/4): 59–102.

  131 Scientific papers addressing the threshold claims of journalists, including Malcolm Gladwell and David Brooks:

  Arneson, Justin J., Paul R. Sackett, and Adam S. Beatty (2011). “Ability-Performance Relationships in Education and Employment Settings: Critical Tests of the More-Is-Better and the Good-Enough Hypotheses.” Psychological Science, 22(10):1336-42.

  Hambrick, David Z., and Elizabeth J. Meinz (2011). “Limits on the Predictive Power of Domain-Specific Experience and Knowledge in Skilled Performance.” Current Directions in Psychological Science, 20(5):275–79.

  (The paper notes: children scoring in the 99.9th percentile on the SAT’s math section by age thirteen are eighteen times more likely to get a math or science Ph.D. than children who “only” scored in the 99.1th percentile.)

  131 Data analysis of NBA body types in this chapter is original, carried out by the author and psychologist Drew H. Bailey. We used data from the NBA combine and from U.S. government sources that are noted in the text.

  133 The 5'3" Muggsy Bogues could dunk:

  Foreman, Tom Jr. “Bogues, Webb Make Case for the Little Guy.” Associated Press, February 16, 1985.

  135 A fascinating account of the “creation” of Yao Ming:

  Larmer, Brook. Operation Yao Ming: The Chinese Sports Empire, American Big Business, and the Making of an NBA Superstar. Gotham, 2005.

  136 Average height of a seventeenth-century Frenchman:

  Blue, Laura. “Why Are People Taller Today Than Yesterday?” Time, July 8, 2008.

  136 J. M. Tanner’s Fetus into Man (Harvard University Press, 1990) served as a source on growth trends in the industrialized world. It is where he recounts: the tale of the identical twin brothers raised in starkly different environments (p. 121); the growth patterns of twins (p. 123); that man did not evolve with the supermarket (p. 130); the leg length disparities between socioeconomic classes (p. 131); work indicating that blind children have distinct growth patterns (p. 146); and rapid leg growth during Japan’s “economic miracle” (p. 159).

  136 The study that accounted for 45 percent of the variance in height with DNA variations also discusses the general finding that height is about 80 percent heritable in a given population:

  Yang, Jian, et al. (2010). “Common SNPs Explain a Large Proportion of the Heritability for Human Height.” Nature Genetics, 42(7):565–69.

  137 On the inability to find height genes:

  Maher, Brendan (2008). “The Case of the Missing Heritability.” Nature, 456: 18–21.<
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  137 Female gymnasts delay menarche, but attain normal adult stature:

  Norton, Kevin, and Tim Olds. Anthropometrica. UNSW Press, 2004, p. 313.

  138 Leg length—and particularly leg growth in Japan—is also discussed in:

  Eveleth, Phyllis B., and James M. Tanner. Worldwide Variation in Human Growth (2nd ed.). Cambridge University Press, 1991.

  138 Charts of leg length by ethnicity:

  Eveleth, Phyllis B., and James M. Tanner. “Chapter 9: Genetic Influence on Growth: Family and Race Comparisons.” Worldwide Variation in Human Growth (2nd ed.). Cambridge University Press, 1990.

  138 The 1968 Mexico City Olympic study (the quote regarding “persistent” ethnic differences appears on p. 73):

  de Garay, Alfonso L., Louise Levine, and J. E. Lindsay Carter, eds. Genetic and Anthropological Studies of Olympic Athletes. Academic Press, 1974.

  140 The original “Allen’s rule” paper:

  Allen, Joel Asaph (1877). “The Influence of Physical Conditions in the Genesis of Species.” Radical Review, 1:108–140.

  140 A massive body of research has extended Allen’s and Bergmann’s rules to humans. For one recent discussion and a listing of confirmatory studies:

  Cowgill, Libby W., et al. (2012). “Development Variation in Ecogeographic Body Proportions.” American Journal of Physical Anthropology, 148:557–70.

  140 The 1998 analysis of body proportions in native populations around the world:

  Katzmarzyk, Peter T., and William R. Leonard (1998). “Climatic Influences on Human Body Size and Proportions: Ecological Adaptations and Secular Trends.” American Journal of Physical Anthropology, 106:483–503.

  141 The 2010 “belly button” study:

  Bejan, A., Edward C. Jones, and Jordan D. Charles (2010). “The Evolution of Speed in Athletics: Why the Fastest Runners Are Black and Swimmers White.” International Journal of Design & Nature, 5(3):199–211.

  Duke press release: “For Speediest Athletes, It’s All in the Center of Gravity.” July 12, 2010.

  9

  We Are All Black (Sort Of)

  Race and Genetic Diversity

  142 Background on the “Out of Africa” hypothesis and previously competing hypotheses:

  Klein, Richard G. “Chapter 7: Anatomically Modern Humans.” The Human Career: Human Biological and Cultural Origins (2nd ed.). University of Chicago Press, 1999.

  143 One example of the human “family tree” diagram:

  Tishkoff, Sarah A., and Kenneth K. Kidd (2004). “Implications of Biogeography of Human Populations for ‘Race’ and Medicine.” Nature Genetics, 36(11): S21–27.

  144 The intrepid band of our ancestors that left Africa was a small group:

  Macaulay, V., et al. (2005). “Single, Rapid Coastal Settlement of Asia Revealed by Analysis of Complete Mitochondrial Genomes.” Science, 308:1034–36.

  Wade, Nicholas. “To People the World, Start with 500.” New York Times, November 11, 1997, p. F1.

  144 Molecular dating and fossil methods for the timing of the human-chimp split and the Out-of-Africa migration:

  Gibbons, Ann (2012). “Turning Back the Clock: Slowing the Pace of Prehistory.” Science, 338:189–91.

  144 A succinct look at how genetic diversity decreases with distance from Africa:

  Prugnolle, Franck, Andrea Manica, and François Balloux (2005). “Geography Predicts Neutral Genetic Diversity of Human Populations.” Current Biology, 15(5):R159–60. See fig. 2.

  146 Kenneth Kidd’s coauthored CYP2E1 paper is an example of his rainbow diagrams that describe genetic diversity:

  Lee, M. Y., et al. (2008). “Global Patterns of Variation in Allele and Haplotype Frequencies and Linkage Disequilibrium Across the CYP2E1 Gene.” The Pharmacogenomics Journal, 8(5):349–56.

  147 An excellent and accessible talk by Sarah Tishkoff on the genetic changes that allowed adult lactose digestion:

  http://www.youtube.com/watch?v=sgNEb0itPOs.

  148 Adult lactose intolerance is common in Rwanda:

  Cox, Joseph A., and Francis G. Elliott (1974). “Primary Adult Lactose Intolerance in the Kivu Lake Area: Rwanda and the Bushi.” American Journal of Digestive Diseases, 19(8):714–724.

  148 A common gene variant confers immunity from a sports doping test:

  Schulze, Jenny Jakobsson, et al. (2008). “Doping Test Results Dependent on Genotype of Uridine Diphospho-Glucuronosyl Transferase 2B17, the Major Enzyme for Testosterone Glucuronidation.” Journal of Clinical Endocrinology & Metabolism, 93(7):2500–2506.

  148 An interesting albeit technical paper on the 99.5 percent DNA similarity of humans:

  Levy, Samuel, et al. (2007). “The Diploid Genome Sequence of an Individual Human.” PLoS Biology, 5(10):e254.

  149 The 2007 scientific breakthrough of the year, “human genetic variation”:

  Pennisi, Elizabeth (2007). “Breakthrough of the Year: Human Genetic Variation.” Science, 318:1842–43.

  149 Local ancestry of Iceland residents identifiable with DNA:

  Helgason, A., et al. (2005). “An Icelandic Example of the Impact of Population Structure on Association Studies.” Nature Genetics, 37(1):90–95.

  149 DNA pinpoints European ancestry to within a few hundred miles:

  Novembre, John, et al. (2008). “Genes Mirror Geography Within Europe.” Nature, 456(7218):98–101.

  149 A computer blindly grouped DNA into major geographic regions:

  Rosenberg, Noah A., et al. (2002). “Genetic Structure of Human Populations.” Science, 298(5602):2381–85.

  149 The Stanford-led study of self-identified race and genetics:

  Tang, Hua, et al. (2005). “Genetic Structure, Self-Identified Race/Ethnicity, and Confounding in Case-Control Association Studies.” American Journal of Human Genetics, 76(2):268–75.

  150 The Stanford press release (“Racial Groupings Match Genetic Profiles, Stanford Study Finds”) for the study can be found here:

  http://med.stanford.edu/news_releases/2005/january/racial-data.htm.

  150 On skin color, UV radiation, and latitude:

  Jablonski, Nina G., and George Chaplin (2000). “The Evolution of Human Skin Coloration.” Journal of Human Evolution, 39:57–106.

  150 The main genetic and geographic clusters of people do “correlate with the common concept of ‘races’”:

  Tishkoff, Sarah A., and Kenneth K. Kidd (2004). “Implications of Biogeography of Human Populations for ‘Race’ and Medicine.” Nature Genetics, 36(11): S21–27.

  150 The genetic backgrounds of African Americans:

  Tishkoff, Sarah A., et al. (2009). “The Genetic Structure and History of Africans and African Americans.” Science, 324(5930):1035–44.

  150 Tishkoff’s “little genetic differentiation” quote can be found in a University of Pennsylvania press release:

  http://www.upenn.edu/pennnews/current/node/3643.

  151 The National Human Genome Research Institute on race, genetics, and genotypic and phenotypic diversity:

  Race, Ethnicity and Genetics Working Group of the National Human Genome Research Institute (2005). “The Use of Racial, Ethnic, and Ancestral Categories in Human Genetics Research.” American Journal of Human Genetics, 77:519–32.

  153 The original ACTN3 paper:

  North, Kathryn N., et al. (1999). “A Common Nonsense Mutation Results in α-Actinin-3 Deficiency in the General Population.” Nature Genetics, 21: 353–54.

  155 The first paper that documented a difference in ACTN3 variant frequency in sprinters and the general population:

  Yang, Nan, et al. (2003). “ACTN3 Genotype Is Associated with Human Elite Athletic Performance.” American Journal of Human Genetics, 73:627–31.

  155 ACTN3 and athletic performance studies in populations around the world:

  Eynon, Nir, et al. (
2012). “The ACTN3 R577X Polymorphism Across Three Groups of Elite Male European Athletes.” PLoS ONE, 7(8):e43132.

  Niemi, A. K., and K. Majamaa (2005). “Mitochondrial DNA and ACTN3 Genotypes in Finnish Elite Endurance and Sprint Athletes.” European Journal of Human Genetics, 13:965–69.

  Papadimitriou, I. D., et al. (2008). “The ACTN3 Gene in Elite Greek Track and Field Athletes.” International Journal of Sports Medicine, 29:352–55.

  Scott, Robert A., et al. (2010). “ACTN3 and ACE Genotypes in Elite Jamaican and US Sprinters.” Medicine & Science in Sports & Exercise, 42(1):107–12.

  Yang, Nan, et al. (2007). “The ACTN3 R577X Polymorphism in East and West African Athletes.” Medicine & Science in Sports & Exercise, 39(11):1985–88.

  ACTN3 data from Japanese sprinters was generously shared by Noriyuki Fuku and Eri Mikami during a visit to the Department of Genomics for Longevity and Health at the Tokyo Metropolitan Institute of Gerontology.

  155 The spread of the ACTN3 X variant in humans may have been an evolutionary adaptation:

  North, Kathryn (2008). “Why Is α-Actinin-3 Deficiency So Common in the General Population? The Evolution of Athletic Performance.” Twin Research and Human Genetics, 11(4):384–94.

  155 The best review of ACTN3 research and the impacts on muscle properties of α-actinin-3 deficiency:

  Berman, Yemima, and Kathryn N. North (2010). “A Gene for Speed: The Emerging Role of α-Actinin-3 in Muscle Metabolism.” Physiology, 25:250–59.

  155 The idea that the ACTN3 X variant may have spread as an adaptation to agriculture is posited on p. 117 of:

  Cochran, Gregory, and Henry Harpending. The 10,000 Year Explosion: How Civilization Accelerated Human Evolution. Basic Books, 2010.

  10

  The Warrior-Slave Theory of Jamaican Sprinting

  159 An overview of theories of Jamaican sprint success (p. 2 has ACTN3 data for Jamaicans and other populations):

  Irving, Rachael, and Vilma Charlton eds. Jamaican Gold: Jamaican Sprinters. University of the West Indies Press, 2010.

  161 Lists of sprinters of Jamaican descent who compete for other countries and of Jamaican sprinters from Trelawny can be found in the annex of:

  Robinson, Patrick. Jamaican Athletics: A Model for 2012 and the World. Black Amber, 2009.