And The Most Efficient Swim Stoke Is…

June 21, 2012 7:35 am 0 comments

Share This:

Subscribe:

Author:

Tags:

Swimmers, I mean top level swimmers, have never agreed about which of two arm movements is most efficient for freestyle swimming. In one corner, we have proponents of the paddle stroke, also known as the deep catch stroke, for which the arm is extended and which pulls the water like a boat paddle. In the other, we have proponents of the propeller stroke, also known as the sculling stroke, for which the arm is bent at the elbow and makes a slight S-shaped curve as it moves through the water. Now, thanks to researchers at Johns Hopkins University, we have our final answer: the deep catch stroke is more effective and more efficient than the sculling stroke. Finding that answer wasn’t easy. A Johns Hopkins news release reports that scientists from the department of engineering used high-precision laser scans and underwater videos of elite swimmers, then turned to animation software to change the shape of the static arm in such a way as to match the video sequence. The team then ran computer simulations to study the flow of fluid around the arm and the forces that acted upon the limb. Each simulation involved about 4 million degrees of freedom and required thousands of hours of computer processing time. Study author Rajat Miittal says his research disproves the long-held conviction of many swim coaches that the sculling stroke delivers more speed. “Sculling, in my view, is a swimming stroke that is based on an incomplete understanding of fluid mechanics,” Mittal said. “We found that lift is indeed a major component in thrust production for both strokes, and that certainly indicates that the arm does not behave simply like a paddle. However, the simulations also indicate that exaggerated sculling motions, which are designed to enhance and exploit lift, actually reduce both the lift and drag contributions to thrust. So, lift is in fact important, but not in the way envisioned by these early coaches who were trying to bring fluid mechanics into swimming.” Got that? Read more from Johns Hopkins.

Leave a Reply


Recent Posts

  • Pain What To Do About The Worst Allergy Season In Years

    What To Do About The Worst Allergy Season In Years

    First, the bad news. Allergy experts remind us that cold winters generally make for bad allergy seasons, and this winter, at least in the northeast, was brutally cold.  And now the good news: Yale immunology researcher Dr. Tao Zheng suggests a few things we can do get through what may be worst allergy season in years. Keep windows closed during pollen season, especially during the day Stay indoors during midday and afternoon hours when pollen counts are highest Take a […]

    Read more →
  • Uncategorized This Year’s Model: Jogger Pants

    This Year’s Model: Jogger Pants

    No, you don’t have jog to wear them, but it helps if you at least look like you jog once in a while. Jogger pants are in. How do we know? Because Google’s Fashion Trends for Spring, an analysis of six billion fashion related searches, puts them near the top of the list, along with tulle skirts. Google reports that all kinds of people–men, women, boys, girls, are searching the term “jogger pants,” and drilling down to take a look […]

    Read more →
  • Pain Women's Health Why Mosquitoes Like You, Or Not

    Why Mosquitoes Like You, Or Not

    There is no scientific evidence that drinking beer keeps mosquitoes away, but does that mean it’s not worth trying? Not at all. Same deal with garlic, which has been proven, at least, to keep other people away. What does keep mosquitoes away? According to researchers at the University of Florida, our genes do, and they also attract mosquitoes. Being thin also seems to dissuade the bugs, as does not being pregnant. And now the news:  A U of Florida news […]

    Read more →
  • Pain This Year’s Ticks Carry Double Whammy

    This Year’s Ticks Carry Double Whammy

    Lyme disease was bad enough, but now, according to disease ecologists at Columbia University, deer ticks have expanded their parasitic payload to include a malaria-like parasite called Babesia microti, which causes babesiosis when transmitted to humans. What’s babesiosis? It’s a lot like Lyme disease, with a flu-like illness, but it can also cause certain types of anemia, and can be fatal in people with suppressed immune systems. And Lyme disease, if left untreated, may lead to problems in the brain and […]

    Read more →
  • Attitude Pain Mindfulness May Ward Off Depression As Well As Drugs

    Mindfulness May Ward Off Depression As Well As Drugs

    What’s better for warding off a relapse of depression: “maintenance antidepressant medication” or mindfulness-based therapy. And the answer is…neither.  Based on the results of a study conducted at the University of Oxford, both practices seem to do the job equally well. Science Daily reports on the research, for which 424 adults with recurrent major depression and taking maintenance antidepressant medication were randomly assigned to come off their medication slowly and receive MBCT (212 participants) or to stay on their medication (212 […]

    Read more →
  • Fitness Gear Pain Muscle-Building Supplements Linked To Cancer

    Muscle-Building Supplements Linked To Cancer

    No, it’s not better to look good than to feel good, especially if looking good requires muscle-building supplements that contain creatine or androstenedione, two additives that may increase the risk of testicular cancer. How do we know? Because a Brown University news release reports that researchers at the school interviewed nearly 900 men, 356 of whom had been diagnosed with testicular germ cell cancer, and 513 who had not, asking not only about their supplement use but also about a wide variety of […]

    Read more →
  • Fitness Pain Many Diet Supplements Contain Dangerous Chemicals

    Many Diet Supplements Contain Dangerous Chemicals

    In December, Canadian authorities banned the sale of diet and workout supplements that contain BMPEA, calling the chemical, which is nearly identical to amphetamine, a “serious health risk.” Curiously, in the United States, the FDA took no such action, even though it had found that nine of 21 supplements tested contained the same chemical as long as two years ago. Strange? It gets more strange. Writing in the New York Times, Anahad O’Connor reports that the federal agency never made […]

    Read more →
  • Fitness Pain No, You Won’t Have A Heart Attack While Exercising, Probably

    No, You Won’t Have A Heart Attack While Exercising, Probably

    The next time your spouse warns you not to push too hard while exercising because you might have a heart attack, remind him or her of the findings of this recent study by the Cedars-Sinai Heart Institute study. Researchers at the institute studied the 1,247 people aged 35-65 from the Portland, Oregon, metropolitan area who had a sudden cardiac arrest between 2002 and 2013. The envelope please… they found that just 5 percent, or 63 people, had a sudden cardiac arrest during […]

    Read more →