How Fast Can Fast Get?

Running and swimming records are broken again and again at almost every international athletics event. But, can human performance continue to improve indefinitely? Will runners continue to accelerate off the starting blocks and reach the finish line in faster and faster times? Will swimmers always be able to dive into the record books with a quicker kick?

Writing in the International Journal of Applied Management Science, researchers from South Korea have analyzed data from sports events over the last one hundred years and have calculated that we could reach the upper limits on elite human performance within a decade.

Yu Sang Chang and Seung Jin Baek of the KDI School of Public Policy and Management in Seoul used non-linear regression models to accurately extrapolate the data from 61 running and swimming events. They have found the "time to limit" to be somewhere between 7.5 and 10.5 years. So, we may still see records being broken at the 2012 Olympics in London and perhaps at Rio 2016, but after that...who knows? The researchers believe their discovery of a "time to limit" has a number of policy implications for the local and national sport associations as well as for the international rule-setting federations.

Of course, US swimmer, Michael Phelps famously proclaimed that, "You can't put a limit on anything. The more you dream, the farther you get." Phelps has set around 40 world records. Sprinter Usain Bolt of Jamaica, similarly shaves split seconds from his 100-metre time almost every time he runs. Countless researchers have previously suggested that humans have a performance limit, Bolt's 9.58 second 100m shattered the previous theoretical running speed limit of 9.60s suggested 40 years ago.

"The limit of speed in sport events has been a popular topic for the public because watching athletes setting new records to win is exciting and stimulating for many sport fans," Chang and Baek suggest. "In addition, setting new world records may even be inspiring to the public because the process of improving and winning the competition reminds them of what they can accomplish in their own life."

Other researchers have criticized the use of linear regression to extrapolate to a limit. However, the present work uses the officially recognized world records on 61 sporting events during the period from 1900 to 2009. (29 running and 32 swimming events all at the Olympic level. "Therefore, this study may be the most comprehensive study undertaken so far," the researchers say.

Their statistical analysis suggests that improvements in running and swimming are slowing down and will eventually reach a maximum in the time period they suggest. However, their analysis does not take into account changes in the rules, measurements, and environmental conditions. If the governing federations move the starting blocks as it were, Phelps' prediction that there are no limits may come true and athletes will continue to make a splash in the record books indefinitely.

Source:  Inderscience Publishers  and Yu Sang Chang, Seung Jin Baek. Limit to improvement in running and swimming. International Journal of Applied Management Science, 2011; 3: 97-120

See also: The Fastest Man On No Legs and Usain Bolt Can Be Even Faster, Researchers Claim

Racial Physiology Differences Determine Race Performances

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."

Jordan Charles (L) and Adrian Bejan Duke University

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."

Source: Duke University and The Evolution of Speed in Athletics, Int. Journal of Design & Nature. Vol. 5, No. 0 (2010) 1–13


See also: The Physiology Of Speed and The Fastest Man On No Legs

Inside An Olympian's Brain

Michael Phelps, Nastia Liukin, Misty May-Treanor and Lin Dan are four Olympic athletes who have each spent most of their life learning the skills needed to reach the top of their respective sports, swimming, gymnastics, beach volleyball and badminton (you were wondering about Lin, weren't you...) Their physical skills are obvious and amazing to watch. For just a few minutes, instead of being a spectator, try to step inside the heads of each of them and try to imagine what their brains must accomplish when they are competing and how different the mental tasks are for each of their sports.


On a continuum from repetitive motion to reactive motion, these four sports each require a different level of brain signal to muscle movement. Think of Phelps finishing off one more gold medal race in the last 50 meters. His brain has one goal; repeat the same stroke cycle as quickly and as efficiently as possible until he touches the wall. There isn't alot of strategy or novel movement based on his opponent's movements. Its simply to be the first one to finish. 

What is he consciously thinking about during a race? In his post-race interviews, he says he notices the relative positions of other swimmers, his energy level and the overall effort required to win (and in at least one race, the level of water in his goggles.) At his level, the concept of automaticity (as discussed in a previous post) has certainly been reached, where he doesn't have to consciously "think" about the components of his stroke. In fact, research has shown that those who do start analyzing their body movements during competition are prone to errors as they take themselves out of their mental flow.


Moving up the continuum, think about gymnastics. Certainly, the skills to perform a balance beam routine are practiced to the point of fluency, but the skills themselves are not as strictly repetitive as swimming. There are finer points of each movement being judged so gymnasts keep several mental "notes" about the current performance so that they can "remember" to keep their head up or their toes pointed or to gather speed on the dismount. There also is an order of skills or routine that needs to be remembered and activated.

While swimming and gymnastics are battles against yourself and previously rehearsed movements, sports like beach volleyball and badminton require reactionary moves directly based on your opponents' movements. Rather than being "locked-in" to a stroke or practised routine, athletes in direct competition with their opponents must either anticipate or react to be successful.

So, what is the brain's role in learning each of these varied sets of skills and what commands do our individual neurons control? Whether we are doing a strictly repetitive movement like a swim stroke or a unique, "on the fly" move like a return of a serve, what instructions are sent from our brain to our muscles? Do the neurons of the primary motor cortex (where movement is controlled in the brain) send out signals of both what to do and how to do it?

Researchers at the McGovern Institute for Brain Research at MIT led by Robert Ajemian designed an experiment to solve this "muscles or movement" question. They trained adult monkeys to move a video game joystick so that a cursor on a screen would move towards a target. While the monkeys learned the task, they measured brain activity with functional magnetic resonance imaging (fMRI) to compare the actual movements of the joystick with the firing patterns of neurons. 

The researchers then developed a model that allowed them to test hypotheses about the relationship between neuronal activity that they measured in the monkey's motor cortex and the resulting actions. They concluded that neurons do send both the specific signals to the muscles to make the movement and a goal-oriented instruction set to monitor the success of the movement towards the goal. Here is a video synopsis of a very similar experiment by Miguel Nicolelis, Professor of Neurobiology at Duke University:


To back this up, Andrew Schwartz, professor of neurobiology at the McGowan Institute for Regenerative Medicine at the University of Pittsburgh School of Medicine, and his team of researchers wanted to isolate the brain signals from the actual muscles and see if the neuron impulses on their own could produce both intent to move and the movement itself. They taught adult monkeys to feed themselves using a robotic arm while the monkey's own arms were restrained. Instead, tiny probes the width of a human hair were placed in the monkey's motor cortex to pick up the electrical impulses created by the monkey's neurons. These signals were then evaluated by software controlling the robotic arm and the resulting movement instructions were carried out. The monkeys were able to control the arm with their "thoughts" and feed themselves food. Here is a video sample of the experiment:

"In our research, we've demonstrated a higher level of precision, skill and learning," explained Dr. Schwartz. "The monkey learns by first observing the movement, which activates his brain cells as if he were doing it. It's a lot like sports training, where trainers have athletes first imagine that they are performing the movements they desire."


It seems these "mental maps" of neurons in the motor cortex are the end goal for athletes to achieve the automaticity required to either repeat the same rehearsed motions (like Phelps and Liukin) or to react instantly to a new situation (like May-Treanor and Dan). Luckily, we can just practice our own automaticity of sitting on the couch and watching in a mesemerized state.



R AJEMIAN, A GREEN, D BULLOCK, L SERGIO, J KALASKA, S GROSSBERG (2008). Assessing the Function of Motor Cortex: Single-Neuron Models of How Neural Response Is Modulated by Limb Biomechanics Neuron, 58 (3), 414-428 DOI: 10.1016/j.neuron.2008.02.033

Meel Velliste, Sagi Perel, M. Chance Spalding, Andrew S. Whitford, Andrew B. Schwartz (2008). Cortical control of a prosthetic arm for self-feeding Nature, 453 (7198), 1098-1101 DOI: 10.1038/nature06996