Type this question in google and its pretty interesting. I don't know any Jamaicans or have any personal observations, so I can only relay what I have read. The two key words for me are Nature and Nurture.
To start with, Jamaica's standard of living seems similar with many African countries. Being South African, I can connect with some of this. 14.5% unemployed, as opposed to 8.1% in the USA. Average income per year is US $2700, as opposed to US $ 32000 in the USA and three homicides on average per day. On the day of Usain Bolt's final the TIMESONLINE.UK reported that even murder held its breath for Usain and no-one died on that day. That is the effect that the Olympics had on Jamaica. Barbara Blake Hannah, a special consultant to the Ministry of Information, Culture and Sports, said: “Sports is one thing that holds Jamaica together. I heard that on the day of Bolt’s 100 metres, no one here was killed."
This quote brings in the next aspect and that is of support and culture. Track and field is the second biggest sport after Cricket. Kids from an early age of competing and pushing speed. And because so many are on the breadline, the only way to get into colleges is through sports scholarships.
There are some sites that say West African's have greater fast twitch fibers through genetics. But there are also many sites that dispute this. One being Prof. Mossison from UTech: "This is a hypothesis. This is not gospel and fixed in stone. It is a hypothesis based on a lot of biochemical research and anatomical research and I will put it down as succinctly as this: Genetics, dietetics and athletics." However looking at the Jamaicans phasic, having relatively narrow hips, and a backbone that angles the pelvis for more high knee lift in comparison to the back being more straight gives athletes faster and leaner power. Further it noticed that the narrower chest of the Jamaicans allows for faster breathing giving more oxygen exchange. The 1968 Games held in Mexico City still had Jamaicans dominating the sprints to prove this trait. These are some of the genetics that could be offered, Prof Morrison said, but he speed gene is a myth. "But you can't knock research because you don't know what they might come up with at some point. My point is, the gene is really in the structure of those limbs. The major thing you want to concern yourself with is, a number of black people has that same thing, so why is it that they don't do well or as well."
Moving to the dietetics, two of Jamaica's staple crops are yams and green bananas. Yams acts as stimulus for a substance produced called Hypo Steroids while green bananas produce phytate that replenishes energy supply in the muscle known as creatine phosphate.
Now you can't just start eating tons of yams and banana and run fast. What has happened is a stable diet started as baby food carried over into adult Olympic performances. Put that together with organized programs for youth and you have incredible adaptation, from training and diet developed over years. So a cycle of anabolic steroid and stimulus from these phosphate substances is being run over again. Prof Morrison goes out a little to say that he believes by the 60 meters when other athletes start to fade, it is the green banana eating Jamaicans that have the edge because of the replenishing of the phosphate.
I come away with this:
- If you have longer limbs and an athlete's body, thank you parents. If you have genes for athleticism use them any way you can. It was a gift and what you were designed to do.
- Keep eating whole foods, like the paleo guidelines offer. Know that is takes years to change and develop your cells and muscles to produce speed to perform. Eating this way needs to be a stable, a lifestyle. It is not a diet that one can wait for it to end. It is a way of sustainability.
- Keep yourself in a community of nurture and support. You need comrades to go the path with you. Follow the Ubuntu way: "I am what I am because of who we all are."