One question we could ask ourselves is whether aspects such as work or the tendency to play sports are fully acquired traits or do they really have an important genetic component . Theodore Garland, a physiologist at the University of California Riverside, with his team, did a series of experiments in which he was able to show, precisely, that there is an important genetic influence. Normal mice run approximately 4 to 6 kilometers each night. Garland took a group of mice and separated them into two groups: those who decided, of their own free will, to run less than a kilometer each night, and those who decided not to run more than normal. The mice could only reproduce with those of their same group. In this way Garland was selecting "elite runners" mice .
After only one generation of offspring, the progeny of those runners, of their own free will, ran even more on average than their parents. And so, generation after generation, when the sixteenth generation of offspring was reached, the mice voluntarily ran 10 kilometers every night. But there were more changes associated with those mice: they had more symmetrical bones, lower body fat, and larger hearts. To make matters worse, the brains of those mice were also different, and Garland suspected that they had to be in those centers that had to do with motivation and reward.
In fact, they did another experiment: They gave them Ritalin , a stimulant that alters the levels of dopamine , which is a neurotransmitter. Normal mice, once they had taken Ritalin, apparently felt a greater sense of pleasure when running, so they started doing it more. But the running mice ran just the same. Whatever Ritalin did in the brains of normal mice, it was already being produced in the brains of running mice. We can say that they were literally addicted to running.
Researchers around the world have begun to explore places in the genome that differ between running and normal mice, especially in the part that has to do with the dopamine-related part of the brain. But of course, they don’t do it simply to understand why rodents want to run – their ultimate goal is to learn about it in humans .
A family of athletes
Obviously, these experiments cannot be done with humans, but we have some examples of a particularly athletic family . The day after doing 11 hours, 20 minutes and 49 seconds in a triathlon, a mark good enough to go to the world championships in Hawaii, Pamela Reed took a plane to take a trip. The flight was delayed and Pamela hid her luggage in a corner and started running around 200 meters. It was like this for an hour. He needed to do this exercise.
A week earlier he had participated in a relay race consisting of enduring eight continuous hours running around a track, and two weeks before the latter he had raced for 31 hours to finish second in the Badwater Ultramarathon, a 135-mile race that He starts in Death Valley and he had already won twice .
His father was tireless. He would get up at 3:30 to go to work in an iron mine and when he returned home he would start doing things in it or repairing his car. According to Pamela Reed herself, her grandfather had a family argument one day and left there in a fury. He walked home which was no less than 300 miles away .
Source | David Epstein , The Sports Gene . Photo |eScience Photo | Harris Rose