Category Archives: Research

Doc Counsilman’s Curiosity Continues

Racing start velocity, body shaving, drag forces, and drinking chocolate milk for a quicker recovery after workouts are just a few of the subjects Joel Stager and his team of researchers at Indiana University’s Counsilman Center have been studying.

The researchers are carrying on the work of James “Doc” Counsilman, regarded as one of the revolutionary coaches in swimming history. From interval training and pace clocks to underwater cameras and streamlining, Counsilman made it his life’s goal to marry the science and art of swimming. His expertise helped Indiana University win six consecutive NCAA championships from 1968 to 1973, and put Gary Hall, Mark Spitz, John Kinsella and others on the Olympic team.

“I was fortunate enough to come here, literally at his (Counsilman’s) urging,” Stager said. “He felt like his big legacy was merging science to the preparation of athletes at the elite level.” A new Endless Pool at the center will be a part of many more research projects, Stager said. One that he is excited to start is a study that will result in an algorithm that will enable a swimmer to instantly know how many calories were burned in a workout. Stroke frequency and distance per stroke, he said, will be the two main elements that will guide this study.

If Counsilman were alive to see the progress the center has made in the past decade, Stager is certain “Doc” would be proud. “He’d be right smack dab in the center of it all,” Stager said. “He loved to innovate and experiment. Nothing was outside his realm of curiosity.”

The above post references the Swimming World artical by Jeff Commings Titled : Doc Counsilman’s Curiosity Lives on at Indiana University’s Counsilman Center – September 10, 2012

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Minimum Water Depths Under Starting Blocks

On July 20, 2012, the Facility Design and Construction Model for the Model Aquatic Health Code (MAHC) was posted for public comment due October 14, 2012.  In section a single sentence could change the industry standard for minimum depths  under starting blocks to 6 feet and 7 inches for a distance of 20 feet.  This could have a significant impact on swimming pools around the country and industry professionals are encouraged to participate in the public input process.  In order to make an informed decision, the following data is offered for consideration. 

Competitive swimmers execute headfirst dive entries from starting blocks into pools where water depths can vary. If the swimmer’s head strikes the bottom of a pool, this could result in damage to the cervical vertebrae, thus may result in quadriplegia. This was a significant topic of conversation in the industry in the early 1980s when a varsity swimmer at a university was injured in practice. Before 1970 this was unheard of, but in the early 70s, goggles were introduced and different methods of completing racing dives were developed to maximize speed and minimize the potential for losing goggles.  

In prevention of Cervical Spinal Injuries (CSI), a cohesive plan currently does not exist for a minimum uniform water depth, which would lessen the likelihood of catastrophic tragedies. “No Diving” signs are posted when the water is less than five feet deep in some states, and four feet in others. There is still more inconsistency. What is the right depth for balancing safety and function for underneath starting blocks? Moreover, should we build all-deep water pools? What depth? And what about recreation swimmers?  

Here’s the Confusion

Up until the early 2000s the industry standard water depths were in the 3 feet 6 inches to 4 feet range. November 2001, the National Federation of State High School Associations (NFHS) changed minimum water depths from 3 feet 6 inches to 4 feet. USA Swimming followed suit with a note that teaching off a starting block shall be limited to 6 feet water depth. 

Policy makers, swimming pool rulebooks, and state swimming pool codes still lack research in regard to water depth requirements under starting blocks. Moreover, water depth requirements under starting blocks in governing bodies’ rulebooks not only conflict with one another but often conflict with state statutes, which may in turn conflict with local county and municipal ordinances.  

The following shows a variance among the four aquatic governing bodies, as well as the YMCA and the American Red Cross, in regard to water depth for headfirst entries. 

Federation Internationale DE Natation (FINA): 4 feet 5 inches.

National Collegiate Athletic Association (NCAA): 4 feet.

National Federation of State High School Associations (NFSHS): 4 feet.

USA Swimming and US Masters Swimming: 4 feet for racing, 6 feet for teaching.

YMCA: 5 feet.

American Red Cross: 9 feet.


The Research

The Counsilman Center for The Science of Swimming completed a study in 2011 on racing start safety published in the International Journal of Aquatic Research and Education.  Joel Stager, Director reports the water depth needed to prevent contact with the bottom of the pool that could result in injury is well beyond 6 feet 7 inches and the critical link to safe starting block starts is education.  In summary this research indicates:

  1. Swimmers go deeper in deeper water
  2. Older swimmers go deeper than younger swimmers
  3. All ages ( and experience levels) of swimmers go shallower when asked to do so
  4. There are differences in head depth as a function of block height
  5. Virtually all starts are fast enough to cause injury if an impact should occur
  6. Very few swimmers go deeper than five feet even in seven feet of water. 

We are at a crossroads between safety versus programming when they should be compatible.  The key to safety in this matter is instruction and how participates learn how to dive.  The reality is no water depth is safe without proper instruction.  When making an informed decision, one must balance the threats and benefits from an activity.  There has been plenty of research on the health advantages of recreation, lesson, fitness, and competitive swimming and how it impacts safety and lifestyle. Here’s a nice shout out to water safety programs and ongoing swim lessons nationwide. Even though more and more people are exposed to a growing number of swimming pools at new aquatic facilities across the nation, drowning death rates in the United States have declined in the last decade according to the Centers for Disease Control and Prevention.  


Should We Build All-Deep Water Pools?

Is the answer that we build all-deep water pools? And if so, how deep? Twenty years ago swimmers swam nearly their entire race at the surface. Today most elite swimmers swim a large percentage of their races 3 to 4 feet below the surface, utilizing a butterfly (dolphin) kicking technique.  

Championship pool depth may impede many instructional, fitness, and recreational opportunities and consequently, revenue potential. And since people frequent pools for a variety of reasons—fitness, relaxation, instruction, competition, and therapy—today’s swimming facilities do not just accommodate competitive swimmers but are multidimensional centers encompassing all types of swimmers.  

To provide a fiscally sustainable facility, multiple users must be able to use the same space for different purposes at different times. Building an all deep-water competitive pool would significantly limit other uses such as recreation, lesson, fitness and therapy.  The following shows preferred water depths for various types of swimmers. 

0 – 3.5 Feet



        Wellness / Therapy 

3.5 – 5 Feet


        Lap Swimming

        Wellness / Therapy 

5 – 10 Feet

        Competitive Swimming

        Water Polo

        Synchronized Swimming 

11.5 Feet +


Unintended Consequences

Some may suggest that the Facility Design and Construction Module is limited to new construction and would not apply to existing facilities.  I would suggest that given the United States legal system this is naive.  I cannot envision an outcome that defines separate solutions water depth solutions for new and older pools.  In 2001 when the NFSH changed the minimum depth standard from 3 feet six inches to 4 feet, many high school pools moved the starting blocks from the shallow end of the pool to the deep end.  For pools without diving wells, this proposed change would likely require structural modifications to the pool shell.  To renovate a six lane 25 yard pool from a maximum water depth of 4 feet to 6 feet 7 inches for a distance of 20 feet in front of the pool edge is estimated to be in the $200,000 range.  Not only will the pool depth be effected but the mechanical equipment will need to be upgraded to services the increased water volume.  For new construction the differential cost is not as great with an estimated increased cost in the $20,000 range.  


The State of Michigan is the only state that requires water depths under starting blocks to be 6 feet 7 inches.  If the MAHC codifies this unique standard it will change the national standard as defined by the governing bodies of sport.  In this writer’s opinion, the unintended consequences maybe the dramatic decline of competitive swimming activities in the United States similar to the effects of removing high dives across the country in the 1980’s and 1990’s.  If this happens what are the negative health effects on childhood obesity and an increased sedentary lifestyle? 


Results – 2012 Olympic Swim Predications

As a follow up to our previous post regarding the expected results of the 2012 Olympic swim competition, this post will present 1) the results of the prediction and 2) speculation as to why the results were what they were.

Prior to 2008, the prediction model successfully predicted 87% of the mean top-eight performances for all Olympic events between 1988 and 2004. In 2008, however, only 34% of the Olympic swimming performances were accurately predicted using the same model. We concluded that the Games were significantly biased due to the introduction of “new-tech” body suits. Given FINA’s 2010 suit policy limiting skin coverage and material type (presumably the cause of the bias), we hypothesized that the model would successfully predict the 2012 Olympic Games, as it had done prior to the suit bias of 2008. However, similar to the 2008 Olympic Games, the results of the 2012 Olympic swimming competition were much faster than expected.

For the 2012 Olympic swim competition, 31% (4/13) of the men’s events and 38% (5/13) of the women’s events were successfully predicted. That is, the model correctly predicted 35% (9/26) of the mean top-eight performances for all events. If we compare 2012 to 2008, about half of the men’s (6/13) and nearly all of the women’s (12/13) events were, on average, faster than the 2008 Games. Tables 1 and 2 show the results of the 2012 Olympic swim predictions. 

Note: Shows a comparison of 2012 Olympic predictions to the 2012 and 2008 actual Olympic performances in each event. 8/13 women’s events were significantly faster than predicted. All events in 2012 but the 50 freestyle were faster than in 2008.

Note: Shows a comparison of 2012 Men’s Olympic predictions to the 2012 and 2008 actual Olympic performances in each event. 9/13 men’s events were significantly faster than predicted. Highlighted events in 2012 but the 50 freestyle were faster than in 2008.

The past two Olympics, 2008 and 2012, have acted to shift the performance curve toward faster rates of improvement. However, the improvement in performance seen in 2008 was much larger than in 2012, suggesting a slowing in performance progression (Figure 1, represented as distances A vs. B). This fact suggests that performances are returning to the expected performance curve (2012 is closer to the curve), or that the performance curve has shifted (Figure 1, represented as red line), and competitors are again approaching the limits to swim performance.




Fear substantially limits the participation in aquatic activity

Change is  hard. Fear makes change even harder. A study performed by Gallup (n=815) and  presented at the 2008 World Aquatic Health™ Conference by Melon Dash  indicates that 64% of Americans are afraid in deep, open water (lakes, rivers,  ocean,…). Forty six percent are afraid in deep water in pools. Even 39% are  afraid to put their heads under water.

I was talking  to Melon Dash a couple years ago and she said something that has been embedded  in my mind ever since. Melon leads the Miracle Swimming Institute that focuses  on training swim instructors to help fearful adults become swimmers. She said  something like, “When you think you are going to die, you are not thinking  about proper stroke technique.” When my kids were in swim classes, a lot of the  focus was on strokes.  Overcoming change  is already a substantial barrier for most people. Overcoming fear is an even  greater obstacle.

It seems  reasonable to surmise that if an individual is afraid of a specific  environment, it is less likely that they would advocate participating in  activities in that environment or purchasing a swimming pool. If that  individual has influence on purchasing decisions in the family, it is  reasonable to conclude that over half of American households may oppose the  idea of engaging in aquatic activities or investing in a pool or hot tub.  Donate to swim programs that help the fearful like the Miracle  Swimming Institute or S.O.A.P.  (Strategies for Overcoming Aquatic Phobias).  Or, donate to  the Step Into Swim™ Campaign that will raise money for  programs like these and other learn-to-swim programs.

Come learn about these programs at the 2012 World Aquatic Health Conference in Norfolk, VA on October 10-12.   Getting more people in the water benefits everyone!

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.