Category Archives: Research

May the Force Not Be With You

Swimmers not only compete against each other but against drag force. Fluid dynamics is the science of dealing with the pressure of fluid flow. In competitive swimming it’s the force that resists the motion of a body moving through the water.

Thrust pushes the swimmer forward and drag is the resistance of the water to the motion of the body. According to Dr. Timothy Wei, “It’s conceptually the exact same problem as an aerodynamicist studying an airplane. They put an engine on an airplane to push the airplane forward and the air is resisting the motion.” Basically, the swimmer is the engine in the pool, and the water is resisting the motion.

 Three Types of Drag

Frictional Drag: this is the dominant drag force of the water along the sides of the swimmer’s body, making it harder to move forward.

Pressure Drag: as the swimmer picks up speed, this is the drag force at the swimmer’s head as the swimmer propels forward through the water.

Wave Drag: Swimming creates waves in the pool causing a barrier wave that the swimmer must constantly push through.


To fight drag forces, swimmers use fluid dynamics to maximize thrust: cupping the hands, churning the arms, kicking hard, keeping the head down, and making the body as narrow an object as possible in the water (streamlining) to efficiently push as much water as possible behind them.

 Missy Franklin, multi-medal swimmer at the 2012 Olympics, says her size 13 feet are hard to find shoes for, but in the pool she uses them as flippers to propel her. With encouragement, passion, and proper technique, swimmers can battle drag force, using their bodies (no matter what size) as engines.

The above blog post was derived from a recent SIKids blog.


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2012 Olympic Swim Predictions

The Counsilman Center for Science and Swimming makes 2012 Olympic Swim Predictions (Men1, Men2, Men3, Men4, Men5 & Women). 

Swimming enthusiasts should expect only a few new World records in London this summer as competitors must forego the now-­‐banned “flotation suits,” the expensive and controversial full-­‐body swim suits that nearly all the swimmers wore at the 2008 Olympic Games.  Joel Stager and his colleagues, Chris Brammer, Kirk Grand and Dave Tanner have created a statistical model based on the times of the Olympic finalists for each Olympic swimming event since 1972.  Over time, swim times should improve in ever-­‐smaller increments as swimmers approach a theoretical limit to human performance.  Unusually steep improvements in time tend to point to some form of recently introduced “bias” to the contests.  Such a jump occurred in 2008 to the extent that those swim times cannot even be used in formulating the model. Earlier recognizable performance “blips” were caused by documented steroid use (1976) and or the unfortunate Olympic Boycott of 1980. In 2008, 65 percent of all of the Olympic swim events were faster than predicted. For the previous five Olympics combined, only 15 percent of the events were faster (or slower) than our model. 

Background: The model crunches the fastest eight male and female performances in Olympic swimming events from 1972 through 2004. Using the mean time across all years, a best-­‐fit power curve was calculated for each swim event. These equations were used to predict the finish times for the 2008 Olympics and will be used again to predict swim times for the current Summer Games. The controversial suits were worn in the Olympic trials in 2008 and also in the Olympics. They were shown to increase swimmers’ buoyancy, particularly with the male swimmers, and this is forbidden by the board that governs international swimming competition.  Stager still expects to see some exciting races and he said some records could fall. As an example, intense competition between Michael Phelps and Ryan Lochte could result in records. Based on their model and swimmers’ times posted at the Olympic trials earlier this summer, other U.S. swimmers such as Matt Grevers, Allison Schmitt, Dana Vollmer, and Missy Franklin all have shots at records. But swimmers from other countries also appear to be competitive (many of whom train in the US) and could give the USA swimmers tough competition for the gold.  Stager and colleagues can be reached at Indiana University’s Counsilman Center 812-­‐856-­‐7160 and or  

* Are entered with a time faster than predicted. All-­‐time top 8 competitors are favored to medal based upon our mathematical projections and the swimmers’ best performances.

** For more information, please see: Brammer, C., Stager, J., & Tanner, D. (2012): Beyond the ‘high-­‐tech’ suits: Predicting 2012 Olympic Swim Performances, Measurement in Physical Education and Exercise Science.

Are Your Arms Paddles or Propellers?

For decades swimmers have been taught that freestyle, AKA “front crawl,” involves keeping their elbows high and using their arms to make an S-shaped pattern underwater.  Known as “sculling,” this technique was developed by Doc Counsilman and helped Indiana University win 6 consecutive NCAA Men’s Swimming and Diving Championships (1968–1973) and 20 consecutive (1961–1980) Big Ten Conference titles.  May of his swimmers went on to set world records and win Olympic gold medals, including Mark Spitz, Gary Hall and Jim Montgomery.  But in recent years, top level swimmers have started to modify their stroke, slowly abandoning the sculling technique in favor of the straight arm “deep catch” technique.

A recent Johns Hopkins study lead by Dr. Rajat Mittal, a mechanical engineering professor and devoted recreational swimmer, compared both swimming techniques using fluid dynamic models, laser scanners and motion capture video.  The study’s results indicates that if all variables are equal “…the deep-catch stroke is far more effective.”

Not surprisingly, the results of this study are likely to pose more questions than it answers.  In the meantime, read the article below and decide for yourself what style arms you have: Paddles or Propellers.

Article Link:

Doc’s Biography:

Positive Impact For Aquatics

Over the past decade, meaningful research has positively impacted the aquatics industry, but additional research is needed.  Areas of additional research are being identified, with many coming from the Model Health Code initiative.  Recent areas of study have included:

  • Supervising Young Children at Public Pools
  • Land-Based vs Underwater Treadmills in Aquatic Exercise
  • Lifeguard Perceptions of CPR
  • How Adolescents Modify Start Entries
  • C-Zones Framework for Examining Drowning
  • Swimmer Hygiene Behavior
  • “Float First” Drowning Prevention Strategy
  • Racing Start Safety – Effects of Water Depth
  • Need to Revise Chlorine Standards for Pools
  • Strength Games From Aquatic Exercise
  • Aquatic Exercise for Asthmatics
  • Older Adult Balance Training Using Water Exercise
  • Swimmer Responses When Caught In A Rip Current

The findings from this research can be referenced in the International Journal of Aquatic Research and Education.

As we look to the future, the question of “How can the industry have the best positive impact for the dollar?” was a recent topic of discussion with industry leader, Bill Kent.  Bill’s challenge was “What if we taught 1 million new swimmers?  Not just one demographic group, but a cross section of the population focusing on adults and children alike.  What impact would this have on inactivity, obesity, and quality of life for the aging society?”

Return on investment:  If each person cost $50 to teach to swim, then it would take $50 million to reach this goal.  While this figure may seem overwhelming, put this into context of the $4.8 billion estimated (300,000 pools X $16,000) spent on the recent VGB mandate and the unknown amount spent on chasing the current changing definition of the ADA mandates.  Joe Hunsaker often said, “Don’t confuse the urgent with the important”.  In reviewing how we have prioritized our investment in the aquatics industry, it appears as an industry that we are guilty of focusing on the urgent and not the important – teaching the life skill of swimming.

The good news is the “Step Into Swim” Campaign Announced by the National Swimming Pool Foundation.  This effort tries to reprioritize the importance of learning the life skill of swimming.  John Puetz, President of the National Swimming Pool Foundation Board of Directors, was quoted as saying “I dream of the day this campaign creates a million MORE swimmers.”  My challenge to the nine organizations who are key to delivering this goal is this: Don’t lose focus on the importance of actually teaching a million new swimmers. After taking care of the urgent, let’s get back to focusing on the important.

Approximately one-third of American men and 40% of women report NO leisure time physical activity.

2008 Physical Activity Guidelines for Americans recommend that adults should be activity. Some physical activity is better than none, and adults who participate in any amount of physical activity gain some health benefits. For substantial health benefits, the Guidelines recommend adults perform at least 150 minutes a week of moderate-intensity aerobic physical activity, 75 minutes a week of vigorous-intensity aerobic physical activity, or an equivalent combination of moderate- and vigorous-intensity aerobic activity.  Overall, approximately 1/3 of American men and nearly 40% of American women report NO leisure time physical activity.

In 2011, only about 45% of Americans overall met the aerobic guidelines. However, prevalence ranges from -65% in 18-24 year old men to a little more than 20% in 75+ year old women.  Women were less likely than men to meet the aerobic guidelines. The percentage of adults who met the guidelines decreases with age. White, non-Hispanic adults were more likely to meet the guidelines for aerobic activity (50.2%, based on leisure-time activity) than other race/ethnic groups (35.0% for Hispanic adults; 39.2% for non­ Hispanic African American adults).

The above data was shared at the Learn-To-Swim Innovator Meeting in Colorado Springs Colorado on April 25, 2012.  This meeting was sponsored by the National Swimming Pool Foundation.