When Will Runners and Swimmers Reach Their Physical Limit?
ScienceDaily (Dec. 23, 2010) — 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
Stress Can Enhance Ordinary, Unrelated Memories
Study about Stress:
ScienceDaily (Dec. 22, 2010) — Stress can enhance ordinary, unrelated memories, a team of neuroscientists has found in a study of laboratory rats. Their results, which appear in the journal PLoS Biology, may bolster our understanding of post-traumatic stress disorder (PTSD) and could offer a pathway for addressing PTSD and related afflictions.
The study was conducted by researchers at the Czech Republic's Academy of Sciences, the State University of New York (SUNY) Downstate Medical Center, and Rockefeller University.
"Our results show that stress can activate memory, even if that memory is unrelated to the stressful experience," explained André Fenton, the study's lead author and a professor at New York University's Center for Neural Science.
"Additional investigations into the effects of stress on memories could shed light on PTSD and other stress-related mood disorders," added Fenton, who directed the studies while he was a Research Scientist in the Czech Republic and an associate professor of physiology and pharmacology at SUNY Downstate.
The study's other authors are: Karel Ježek of the Czech Republic's Academy of Sciences; Benjamin Lee and Eduard Kelemen of SUNY Downstate; and Katharine McCarthy and Bruce McEwen of Rockefeller University.
A common feature of PTSD and various mood and anxiety disorders is the formation of negative associations from otherwise innocuous stimuli or the recall of negative memories stimulated by unrelated, neutral circumstances. What's less clear is how stress influences these phenomena.
To explore the impact of stress on these disorders, the researchers conducted several experiments using laboratory rats.
In these experiments, rats learned to make distinctions between left and right in a T-shaped maze. One day later, the researchers induced stress in the rats through a commonly practiced technique -- placing them in a bucket of water in which they had to swim. Other rats were placed in shallow water, where swimming was not necessary. Subsequent to this procedure, the rats were again tasked with navigating the maze. Their results showed that the rats who had undergone the stressful swim showed better memory for which way to turn in the T-maze than those placed in shallow water.
To test the validity of their findings -- that the memory for navigating the maze was enhanced by the stressful swim and not other forces -- the researchers conducted a series of additional experiments. These procedures ruled out that learning the maze itself was a source of stress and showed a clear link between the stress induced by the swim and changes in the memories of navigating the maze, even though the changed memories were unrelated to the stressful experience.
These results show that stress can reactivate unrelated memories, leading the authors to hypothesize that, in humans, traumatic stress might reactivate non-traumatic memories and link them to the traumatic memory, thereby facilitating the pathological effects seen in post-traumatic stress disorder and other conditions
Credits: Science Daily
Do you believe in a "block" that swimmers will face in their lifetime when they just can't get any faster? How close do you think you are to that block?