Reddit reviews The Sports Gene: Inside the Science of Extraordinary Athletic Performance

There's a hard limit on human reaction speed which doesn't have anything to do with overcoming the inertia of your arm's mass. It's about 50 milliseconds. Still enough time to throw more than 3 punches in a second, but I can see how that might overall be the high end limit. Who am I to argue with Bruce Lee's instructor?

I recommend the book The Sports Gene by David Epstein if you're interested in the topic. Some of the more interesting bits of the book involve exploring the hard limits of world class athletes. For instance, the fastest reaction time among boxers was Muhammad Ali, who was very, very close to this theoretical 50 millisecond reaction time....something like 56 or so. If there are people with faster reflexes, they have never been tested.

Another interesting fun fact: the physical characteristic that professional baseball players have isn't reaction time. It's eyesight. The theoretical limit on that is something like 20/8 vision, which is found in about 1 in 10,000 normal people, but about 1 in 20 professional baseball players.

I agree with the premise that 13 year olds should focus on sprinting regularly and improving mechanics. I’d like to address a few of the ideas that you expressed past that point.

> I’d be in the top 10 sprinters of all time if I used the most expensive training philosophies

With all due respect, I think this underestimates the significant role of genetics in sprinting performance. Following the methods you described will likely prove difficult for a 13 year old due to financial barriers.

Because I’m not fully familiar with Adarian Barr, Chong Xie, or David Weck, I won’t criticize their philosophies on running. It’s worth noting that none of them have trained or had a significant role in training sub 9.8 sprinters, despite having (at least in Adarian Barr’s case) decades to do so. All three of the mentioned philosophies are linked to businesses that promote to individual athletes the idea that great athleticism stems from learning to move properly. Those who want to learn more will find that the bulk of the information is only accessible through clinics ($100+ not including travel costs), expensive books ($99 in one case), and subscriptions. For comparison, Ralph Mann’s The Mechanics of Sprinting and Hurdling, a full discussion of USATF biomechanist Ralph Mann’s philosophy on sprinting, is available for $25. It’s rather dense and it isn’t free of its own controversy, but the book is full of well accepted conclusions that are solidly grounded in the kinematics of sprinting. The main conclusions are affordable and easily accessible, and athletes can fill their gaps in knowledge (perhaps from the sources you mentioned) or learn to implement (link for example) the ideas for free on the internet.

At the rarefied peak of sprint performance, genetics are extremely important. Of the 10 men (including those thrown off of IAAF record books for doping) to run under 9.8 seconds in the 100 meters, all 10 descend from people brought to the Americas from Africa as slaves, and half are of Jamaican descent. That’s not meant to deny the possibility of people from other parts of the world running sub 9.8 times—I’m confident we will see it this century—but rather to highlight the most plainly seen evidence that certain genetic traits (long legs, for example) that may concentrate in a given population confer a higher likelihood of sprinting success. For a more detailed look at the role of genetic traits in sports performance, check out David Epstein’s The Sports Gene.

While we agree that sprinting performance can be improved far more than many expect, the final ability of any given athlete is severely limited by genetics. Research indicates that the fastest sprinters at adulthood were also the fastest in childhood, and that the recalled times of NCAA sprinters (the highest level of US adult sub elite competition) in their early teens were far faster than those of their peers. Improving biomechanics is a great way to improve speed. However, in light of the evidence, it can’t be concluded that they will form a route for ordinary athletes to run 100 meter times that only a few will ever run.

There's a book on this nature vs. nurture debate when it comes to athletic performance: The Sports Gene.
https://www.amazon.com/dp/B00AEDDQKE

Here's an interview with the author:
https://www.npr.org/2013/08/05/209160709/talent-or-skill-honing-in-on-the-elusive-sports-gene

Relevant excerpt from the interview:
"...what genetics is teaching us is the more important kind of talent is actually your biological setup to respond well to training, your ability to get more benefit from your one hour of training than your training partner's one hour of training, and that is emerging as the real talent."