Optimum running speed is stride toward understanding human body form
March 19, 2009 by Jill Sakai(PhysOrg.com) -- Runners, listen up: If your body is telling you that your pace feels a little too fast or a little too slow, it may be right.
A new study, published online March 18 in the Journal of Human Evolution, shows that the efficiency of human running varies with speed and that each individual has an optimal pace at which he or she can cover the greatest distance with the least effort.
The result debunks the long-standing view that running has the same metabolic cost per unit of time no matter the speed — in other words, that the energy needed to run a given distance is the same whether sprinting or jogging. Though sprinting feels more demanding in the short term, the longer time and continued exertion required to cover a set distance at a slower pace were thought to balance out the difference in metabolic cost, says Karen Steudel, a zoology professor at the University of Wisconsin-Madison.
However, Steudel and Cara Wall-Scheffler of Seattle Pacific University have now shown that the energetic demands of running change at different speeds. "What that means is that there is an optimal speed that will get you there the cheapest," metabolically speaking, Steudel says.
Peak efficiency was determined by measuring runners' metabolic rates at a range of speeds enforced by a motorized treadmill. Metabolic energy costs increased at both fast and slow speeds and revealed an intermediate pace of maximal efficiency.
The most efficient running speed determined in the study varied between individuals but averaged about 8.3 miles per hour for males and 6.5 miles per hour for females in a group of nine experienced amateur runners. Much of the gender difference may be due to variations in body size and leg length, which have been shown to affect running mechanics, Steudel says. In general, the larger and taller runners had faster optimum speeds.
Interestingly, the slowest speeds — around 4.5 miles per hour, or about a 13-minute mile — were the least metabolically efficient, which Steudel attributes to the gait transition between walking and running. For example, she points out, both a very fast walk and a very slow run can feel physically awkward.
While holding great interest for athletes and trainers, the mechanics of running may also hold clues to the evolution of the modern human body form: tall and long-limbed with broad chests and defined waists.
Modern humans are very efficient walkers and fairly good runners, Steudel says, and efficient locomotion probably provided our ancestors with an advantage for hunting and gathering food. Distant ancestral forms, the australopithecines, had shorter, boxier frames with stubbier legs.
"They wouldn't have had noticeable waists — their torso looked more like the torso of an ape, except they were walking on two legs," Steudel says. "With the genus Homo, you start getting taller individuals, larger individuals, and they started developing a more linear body form" with distinct waists that pivot easily, allowing longer and more efficient strides.
Human walking is also known to have an optimally efficient speed, so the new findings may help researchers determine the relative importance of the different gaits in driving human evolution, Steudel says. "This is a piece in the question of whether walking or running was more important in the evolution of the body form of the genus Homo."
More information: http://www.elsevie … #description
-
The mechanics of foot travel
Sep 15, 2005 |
not rated yet |
0
-
Study: Long legs are more efficient
Mar 12, 2007 |
not rated yet |
0
-
Was ability to run early man's Achilles heel?
Sep 11, 2007 |
not rated yet |
0
-
Humans hot, sweaty, natural-born runners
Apr 16, 2007 |
not rated yet |
0
-
Jogging with your favorite music
Apr 03, 2005 |
not rated yet |
0
-
Engineers build first sub-10-nm carbon nanotube transistor
Feb 01, 2012 |
4.9 / 5 (33) |
30
-
Something old, something new: Evolution and the structural divergence of duplicate genes
Jan 31, 2012 |
4.6 / 5 (7) |
1
-
The hidden nanoworld of ice crystals: Revealing the dynamic behavior of quasi-liquid layers
Jan 30, 2012 |
5 / 5 (4) |
1
-
Stock market network reveals investor clustering
Jan 27, 2012 |
3.9 / 5 (23) |
8
-
Of microchemistry and molecules: Electronic microfluidic device synthesizes biocompatible probes
Jan 26, 2012 |
5 / 5 (2) |
0
-
Factors affecting beet root cell membrane
18 hours ago
-
Stem cell question.
Feb 10, 2012
-
Protease cleavage
Feb 10, 2012
-
Pertubance in a model
Feb 10, 2012
-
Cancer drugs and Alzheimer's, Oh my!
Feb 09, 2012
-
Squishing cells
Feb 09, 2012
- More from Physics Forums - Biology
More news stories
A mitosis mystery solved: How chromosomes align perfectly in a dividing cell
Although the process of mitotic cell division has been studied intensely for more than 50 years, Whitehead Institute researchers have only now solved the mystery of how cells correctly align their chromosomes during symmetric ...
14 hours ago |
4.5 / 5 (22) |
0
|
Researchers find extensive RNA editing in human transcriptome
In a new study published online in Nature Biotechnology, researchers from BGI, the world's largest genomics organization, reported the evidence of extensive RNA editing in a human cell line by analysis of RNA-seq data, demons ...
14 hours ago |
5 / 5 (4) |
0
|
The proteins ensuring genome protection
Researchers from the University of Geneva (UNIGE), Switzerland, have discovered the crucial role of two proteins in developing a cell 'anti-enzyme shield'. This protection system, which operates at the level of molecular ...
14 hours ago |
5 / 5 (3) |
0
|
Entire genome of extinct human decoded from fossil
(PhysOrg.com) -- In 2010, Svante Pääbo and his colleagues presented a draft version of the genome from a small fragment of a human finger bone discovered in Denisova Cave in southern Siberia. The ...
Feb 07, 2012 |
4.7 / 5 (60) |
51
|
Why are there so few fish in the Earth's oceans?
(PhysOrg.com) -- A Stony Brook University researcher has found that, contrary to popular belief, there are not plenty of fish in the sea.
Feb 08, 2012 |
4.3 / 5 (19) |
27
|
Japan's Fukushima reactor may be reheating: operator
Temperature readings at one of the crippled Fukushima nuclear reactors have risen above Japan's stringent new safety standard but there was no immediate danger, its operator said Sunday.
Scientists discover molecular secrets of 2,000-year-old Chinese herbal remedy
For roughly two thousand years, Chinese herbalists have treated Malaria using a root extract, commonly known as Chang Shan, from a type of hydrangea that grows in Tibet and Nepal. More recent studies suggest that halofuginone, ...
New method to examine batteries -- MRI from the inside
There is an ever-increasing need for advanced batteries for portable electronics, such as phones, cameras, and music players, but also to power electric vehicles and to facilitate the distribution and storage of energy derived ...
Google might launch Drive for cloud storage soon
(PhysOrg.com) -- Google's next big move, according to the Wall Street Journal, is a cloud storage service called Drive. Hardly first to the plate, Google is simply catching up to introducing its cloud reposi ...
Lab study raises questions over nano-particle impact
Tests involving chickens have raised questions about the impact on health from engineered nano-particles, the ultra-fine grains commonly used in drugs and processed foods, scientists said on Sunday.
Starve a virus, feed a cure? Findings show how some cells protect themselves against HIV
A protein that protects some of our immune cells from the most common and virulent form of HIV works by starving the virus of the molecular building blocks that it needs to replicate, according to research published online ...