#41. A Summary of ‘The Sports Gene: Inside the Science of Extraordinary Athletic Performance’ by David Epstein


‘The Sports Gene: Inside the Science of Extraordinary Athletic Performance’ by David Epstein (Current Hardcover; August 1, 2013)

Table of Contents:

i. Introduction/Synopsis


Section A. Height and Skeletal Structure (and an Introduction to Heritability and Genetics)

1. Nature and Nurture in Height and Skeletal Structure

2. An Introduction to Heritability and Genetics

3. Height and Skeletal Structure in the NBA

  • a. Height in the NBA
  • b. Skeletal Structure in the NBA (the Power of Wingspan)

4. Skeletal Structure in Long-Distance Running

5. Skeletal Structure in Sprinting and Swimming (and Other Sports)

  • a. Sprinting and Swimming
  • b. Skeletal Structure in Other Sports

Section B. Muscle

6. Muscle Mass

  • a. Muscle Mass Potential
  • b. Muscle Mass and Strength Increase through Weight Training

7. Fast-Twitch and Slow-Twitch Muscle Fibers

Section C. Aerobic Capacity (VO2max)

8. Baseline Aerobic Capacity

  • a. Blood Volume (and Blood Doping)
  • b. Red Blood Cell and Hemoglobin Volume (and More Blood Doping)

9. Increasing Aerobic Capacity through Exercise (and Altitude)

  • a. Exercise
  • b. Altitude


Section D. East Africa

10. Why So Many Elite Distance Runners Hail from East Africa (Part I): Altitude and Latitude

  • a. The Elevation Sweet Spot
  • b. The Equator (and the Nilotic Body Type)

11. Why So Many Elite Distance Runners Hail from East Africa (Part II): The Kalenjin and the Oromo Tribes (Thin Lower Legs and Cattle-Raiding Ancestors)

  • a. Thin Lower Legs
  • b. Cattle-Raiding Ancestors

12. Cultural Practices and Values in Kenya and Ethiopia

Section E. West Africa

13. Why So Many Elite Sprinters Have Origins in West Africa

14. Jamaican Sprinters

  • a. The Sprinting Culture in Jamaica
  • b. The Trelawny Population


15. Motivation

16. Pain and Injury

  • a. Pain
  • b. Injury

17. Conclusion

i. Introduction/Synopsis

What does it take to become an elite athlete? The intuitive answer for most of us is that it probably takes some lucky genes on the one hand, and a whole heck of a lot of hard work on the other. Specifically, that we may need to be blessed with a particular body type to excel at a particular sport or discipline (after all, elite marathon runners tend to look far different than elite NFL running backs, who in turn tend to look far different than elite swimmers), but that beyond this it is practice and diligence that paves the way to success. When we look at the science, though—as sports writer David Epstein does in his new book The Sports Gene: Inside the Science of Extraordinary Athletic Performance—we find that the story is much more complicated than this. In general terms we find that nature and nurture interact at every step of the way in the development of an elite athlete, and that biology plays far more of a role (and in far more ways) than we may have expected.

To begin with, when it comes to physiology, we find that genetics not only has a large role to play in influencing our height and skeletal structure (as we would expect), but that genes also influence physiology in many other ways that are important when it comes to elite sports. For example, we find that people naturally vary widely in all of the following ways: the size of our heart and lungs, and the amount of red blood cells and hemoglobin that pumps through our veins; the specific type of muscle fibers that are most prevalent in our bodies (and the specific number of each); as well as our visual acuity—and again, all of these factors play a significant role in determining just how athletic we will be (and in what sports we will excel).

Second, when it comes to training, we find that hard work is not all there is to it. For genetics not only shapes our physiology, but also how our physiology responds to training (including how much muscle mass and aerobic capacity we are able to build through exercise). The fact is that we naturally vary widely in just how much we respond to exercise (to the point where some of us improve dramatically through exercise, whereas others of us respond hardly at all). And we also respond differently to different training regimens (to the point where a training regime that works well for one person may in fact harm another).

And while we may wish to take credit for just how hard we train, here too genetics is found to play a role. For it turns out that we differ widely in just how naturally disposed we are to push ourselves. And over and above this, genes also influence how much we experience pain, such that even among those who experience the same desire to push themselves (both in training and in competition), one may find it much easier to handle the pain involved than the other—which, of course, can have a big impact on results.

And speaking of pain, our genes even influence how easily we injure and how well we recover from our injuries—which, once again, has a significant impact on performance.

As an added bonus, Epstein not only covers which biological factors have an impact on sports performance, but the evolutionary story behind these biological factors (including why different populations that have adapted to different environments have come to acquire traits that make them well-disposed to different sports and disciplines [for example, why many elite marathoners have origins in East Africa, many elite sprinters have origins in West Africa, and many elite swimmers and weight-lifters have origins in Europe]).

In short, then, biology plays much more of a role in elite athletic performance that we may have realized. Not that the point of the book is to say that athletic performance is all in our genes. Just the contrary, as mentioned above the book makes the point that genes always interact with the environment to produce athletic outcomes. Genes are essential in shaping the athlete, but just as essential is the athlete’s upbringing and culture, and that they do in fact get the training that is needed to make the most of their natural talents.

Here is David Epstein discussing his new book:

What follows is a full executive summary of The Sports Gene: Inside the Science of Extraordinary Athletic Performance by David Epstein


Section A. Height and Skeletal Structure (and an Introduction to Heritability and Genetics)

1. Nature and Nurture in Height and Skeletal Structure

Height and skeletal structure is one area where it is easy to see that genetics plays a dominant role. Just compare yourself with your parents and/or children, and chances are the apple hasn’t fallen too far from the tree. If you want to get scientific, though, it has been shown that about 80% of the variability in height in industrialized nations, for example, may be attributed to genes (loc. 2015). As Epstein explains, “repeatedly, studies of families and twins find the heritability of height to be about 80 percent. That means that 80 percent of the difference in height between people in the group that is being studied is attributable to genetics, and around 20 percent to the environment” (loc. 2015).

When it comes to the length (and girth) of particular bones in the body, this too is largely determined by genetics (as we would expect). However, it is interesting to note that both the length and girth of bones can be modified through training. For example, the exercise and nutrition researcher Francis Holway “measured the forearms of a group of tennis players ranked in the top twenty in the world and found that their racket arms grew slightly differently from their nonracket arms. The racket-side forearm bones of the players grew around a quarter-inch longer than the forearm bone of the nonracket arm. And the elbow joint widened a centimeter. Like muscle, bone responds to exercise. Even nonathletes tend to have more bone in the arm they write with simply because they use it more, so the bone becomes stronger and capable of supporting more muscle. ‘It’s just amazing how the bone can adapt to repeated stress,” Holway says. Those tennis pros literally served and volleyed their ways to longer forearms” (loc. 1850). Still, the degree to which bones can be lengthened (or strengthened) through exercise and training is fairly limited.

2. An Introduction to Heritability and Genetics

Returning to height now, while the influence of genes on height is well-established, what is not so well established is just what genes are responsible for this. Studies that compare the heights of individuals and their genes have found an enormous number of genes that seem to contribute to height, but researchers are still far from identifying all of the genes at play here. As the author explains, “a 2010 study in Nature Genetics needed 3,925 subjects and 294,831 single nucleotide polymorphisms—spots of DNA where a single letter can vary between people—to account for just 45 percent of the variance in height between adults, and that’s the best any study has done. Finding all the height genes will take much larger and more complex studies than scientists presumed a decade ago [when the human genome was first sequenced]” (loc. 2031).

*For prospective buyers: To get a good indication of how this (and other) articles look before purchasing, I’ve made several of my past articles available for free. Each of my articles follows the same form and is similar in length (15-20 pages). The free articles are available here: Free Articles

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