*I experienced Alaskan husky desire the hard way. On my first and only dogsled trip, in 2010 over the frozen Boundary Waters of Minnesota, my lead husky was a retired racer who was—I later learned—one of Zorro’s sons. I needed about one hundred meters of forceful braking to get the dogs to pause atop a frozen lake. But as soon as I eased up on the brake and looked to the side, the team bolted. I was tossed off the sled and had to chase it for a quarter mile, until the sled got wedged between trees on a tiny frozen island. Lucky for me, as I’m pretty sure I would’ve given up well before Zorro’s progeny.
*Anything that can be bred for must have a genetic component, or else the breeding would not work. Researchers have managed to successfully breed rodents for some bizarre traits, like voluntary gnawing on their own toes. Just as with voluntary running, if toe-masticating mice are bred with one another, generations down the line they produce progeny that will completely bite their toes off.
*In her engrossing book Gifted Children: Myths and Realities, psychologist Ellen Winner coined the phrase “rage to master” to describe one of the primary qualities of gifted children. She describes it as intrinsic motivation and “intense and obsessive interest.” In a sentence that seems as if it were made to describe Tiger Woods or Mozart, she writes: “The lucky combination of obsessive interest in a domain along with an ability to learn easily in that domain leads to high achievement.”
*A troubling trend in high school sports is the increasing number of states that are allowing health care providers who have little or no cardiovascular training—and thus no chance of identifying a dangerous heart murmur—to conduct the preparticipation screening of athletes. In 1997, eleven states allowed chiropractors, herbalists, or other nonphysicians to perform the exams. By 2005, that number had increased to eighteen states, with three states—California, Hawaii, and Vermont—allowing high schools to decide who can perform the exams.
*There were exceptions in my interviews, like ex–NFL quarterback Sean Salisbury: “I don’t want to know what I’m going to get when I’m eighty-two.”
*Work on the COL5A1 gene has also found that people with a particular variant are less flexible and may have a benefit in running. The connection could be stiffness of the Achilles tendon, which would allow it to store more elastic energy—again, recall high jump champion Stefan Holm and his stiff Achilles tendon—and improve running economy. In one novel study, athletes with the “inflexible” version of the gene were faster in the running section of an Ironman, but not in the swim or the bike. That is, only in the part of the race when they fully engaged their Achilles tendon did they perform better. The inflexible gene variant, though, is also associated with increased risk of Achilles tendon injury.
*The increase in dopamine in the frontal cortex might be helpful for baseball hitters who need to be “hyperalert” and mentally flexible, Goldman says. Amphetamines raise dopamine levels and were a staple of baseball for decades, where they were known colloquially as “greenies.” MLB banned amphetamines in 2006, and suddenly the number of players who received doctors’ prescriptions for ADHD drugs, stimulants similar to amphetamine, jumped from 28 to 103 in a single season. One doctor I interviewed who works with major leaguers said that he prescribed Adderall to eight pro players who came in with ADHD symptoms. “The diagnostic is an interview,” the doctor says, “and it can be very easy to fake.” All eight players, he says, had higher batting averages the following season.
*There are, however, a few interesting anecdotes. Identical twin sisters and elite U.S. sprinters Me’Lisa and Mikele Barber train separately. They have 100-meter personal bests that are 0.07 of a second apart.
The Sports Gene: Inside the Science of Extraordinary Athletic Performance Page 40