Featured Research

from universities, journals, and other organizations

For speediest athletes, it's all in the center of gravity

Date:
July 13, 2010
Source:
Duke University
Summary:
In the record books, the swiftest sprinters tend to be of West-African ancestry and the faster swimmers tend to be white. A study of the winning times by elite athletes over the past 100 years reveals two distinct trends: not only are these athletes getting faster over time, but there is a clear divide between racers in terms of body type and race. Researchers now argue that the answer lies in athletes' centers of gravity. That center tends to be located higher on the body of blacks than whites. The researchers believe that these differences are not racial, but rather biological.

In the record books, the swiftest sprinters tend to be of West African ancestry and the faster swimmers tend to be white.

A study of the winning times by elite athletes over the past 100 years reveals two distinct trends: not only are these athletes getting faster over time, but there is a clear divide between racers in terms of body type and race.

Last year, a Duke University engineer explained the first trend -- athletes are getting faster because they are getting bigger. Adrian Bejan, professor of engineering at Duke's Pratt School of Engineering, now believes he can explain the second trend.

In a paper published online in the International Journal of Design and Nature and Ecodynamics, Bejan, and co-authors Edward Jones, a Ph.D. candidate at Cornell University currently teaching at Howard University, and Duke graduate Jordan Charles, argue that the answer lies in athletes' centers of gravity. That center tends to be located higher on the body of blacks than whites. The researchers believe that these differences are not racial, but rather biological.

"There is a whole body of evidence showing that there are distinct differences in body types among blacks and whites," said Jones, who specializes in adolescent obesity, nutrition and anthropometry, the study of body composition. "These are real patterns being described here -- whether the fastest sprinters are Jamaican, African or Canadian -- most of them can be traced back generally to Western Africa."

Swimmers, Jones said, tend to come from Europe, and therefore tend to be white. He also pointed out that there are cultural factors at play as well, such as a lack of access to swimming pools to those of lower socioeconomic status.

It all comes down to body makeup, not race, Jones and Bejan said.

"Blacks tend to have longer limbs with smaller circumferences, meaning that their centers of gravity are higher compared to whites of the same height," Bejan said. "Asians and whites tend to have longer torsos, so their centers of gravity are lower."

Bejan and Jones cite past studies of the human body which found that on average, the center of gravity is about three percent higher in blacks than whites. Using this difference in body types, the researchers calculated that black sprinters are 1.5 percent faster than whites, while whites have the same advantage over blacks in the water. The difference might seem small, Bejan said, but not when considering that world records in sprinting and swimming are typically broken by fractions of seconds.

The center of gravity for an Asian is even more advantageous to swimming than for a white, but because they tend not to be as tall, they are not setting records, Bejan said.

"Locomotion is essentially a continual process of falling forward," Bejan said. "Body mass falls forward, then rises again. Mass that falls from a higher altitude falls faster. In running, the altitude is set by the location of the center of gravity. For the fastest swimmers, longer torsos allow the body to fall forward farther, riding the larger and faster wave."

The researchers said this evolution of body types and increased speeds can be predicted by the constructal theory, a theory of natural design developed by Bejan that explains such diverse phenomena as river basin formation and basis of animal locomotion (www.constructal.org).

Jones said that the differences in body densities between blacks and whites are well-documented, which helps explain other health differences, such as the observation that black women have a lower incidence of osteoporosis than white women because of the increased density of their bones.

Jones notes that cultural issues can play a role in which form of athletic competition someone chooses, and therefore might excel in.

"When I grew up in South Carolina, we were discouraged from swimming," said Jones, who is black. "There wasn't nearly as much encouragement for us as young people to swim as there was for playing football or basketball. With the right encouragement, this doesn't always have to be the case -- just look at the Williams sisters in tennis or Tiger Woods in golf."

This analysis was supported by the National Science Foundation.


Story Source:

The above story is based on materials provided by Duke University. Note: Materials may be edited for content and length.


Cite This Page:

Duke University. "For speediest athletes, it's all in the center of gravity." ScienceDaily. ScienceDaily, 13 July 2010. <www.sciencedaily.com/releases/2010/07/100712103349.htm>.
Duke University. (2010, July 13). For speediest athletes, it's all in the center of gravity. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2010/07/100712103349.htm
Duke University. "For speediest athletes, it's all in the center of gravity." ScienceDaily. www.sciencedaily.com/releases/2010/07/100712103349.htm (accessed October 20, 2014).

Share This



More Science & Society News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
Your Birth Season Might Determine Your Temperament

Your Birth Season Might Determine Your Temperament

Newsy (Oct. 20, 2014) A new study says the season you're born in can determine your temperament — and one season has a surprising outcome. Video provided by Newsy
Powered by NewsLook.com
How Nigeria Beat Its Ebola Outbreak

How Nigeria Beat Its Ebola Outbreak

Newsy (Oct. 20, 2014) The World Health Organization has declared Nigeria free of Ebola. Health experts credit a bit of luck and the government's initial response. Video provided by Newsy
Powered by NewsLook.com
Ebola Worries End for Dozens on U.S. Watch Lists

Ebola Worries End for Dozens on U.S. Watch Lists

Reuters - US Online Video (Oct. 20, 2014) Forty-three people who had contact with Thomas Eric Duncan, the first person diagnosed with Ebola in the U.S., were cleared overnight of twice-daily monitoring after 21 days of showing no symptoms. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Science & Society

Business & Industry

Education & Learning

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins