Science of Performance: Troubleshooting

By Dr. G. John Mullen, PT, DPT, CSCS of Swimming Science, Center of Optimal Restoration , and Mullen Physical Therapy, Creator of Swimmer’s Shoulder System, Swimming Science Research Review, and Swimming Troubleshooting System, Swimming World correspondent

SANTA CLARA, California, October 4. SWIMMING can be as complex as you make it. Everyone has seen coffee shop coaches, simply sitting on pool decks with a drink in one hand, talking to their co-coaches about last night’s sporting event. Often times these coaches have their backs turned to the pool, a true atrocity for all parties. On the other hand, elite coaches integrate physiology, biomechanics, psychology, anatomy, dry-land, prevention/rehabilitation, nutrition, and much more. These factors influence the difficulty of sport, not just swimming, but luckily, a lot of these categories are linked and complement each other. Elite coaching is a never ending, tireless effort, striving for improvement like the best swimmers, as swimming is unique, complex sport. Although coaching swimming has many similarities with other sports, many distinctions exist:

Horizontal position: Many ground-based sports have a vertical position, altering the orientation of the lungs and body. This orientation greatly impacts the demands of the sport. [INSERT: SWIMMING POSITION]
Minimal use of ground reaction force: In swimming, the limited interactions with the ground (other than the start in turn) minimize the importance of creating “ground reaction force” a necessity in other sports.[INSERT: GRF]
Water as a medium: Water alters movement in many ways. For swimming, adding resistance and causing numerous alterations in drag are just the beginning. Water cools the body, likely decreasing heat accumulation and fatigue.
Now, these are just a few differences between swimming and other sports, as many others exist, yet many insist on using principles from other sports and exercise.
In my Doctorate program, we went over gait and running biomechanics in excessive detail. This was addressed to the pathological population, but as an athlete, I sought information on sprint running. One Ph.D. candidate and I shared an interest in performance and he took the time to teach me a lot on running and the simple equation for running success: stride rate x stride length = running speed. That’s it! Two variables, how is it that simple?
This simplistically blew my mind, but was only the beginning. Since learning this simple equation, I have tried applying it to swimming with no chagrin. It seems swimming is more complex.
Swimming Complexity
Like running, swimming speed is the product of stroke rate and stroke length, but limitations of these factors are the tough part, being more extensive than running. The complexity of the sport still results in discoveries of new stroke biomechanics. Dr. Prins of the University of Hawaii said in a Swimming Science interview:

“Elite athletes have very few technique flaws, but breakout velocity can vary widely between elites. That will be the next key research area. If there is a common flaw, it is slipping water on the weak side….Future research will address “interference drag,” which refers to body parts creating drag upon each other. Soni’s breaststroke pull (rounding out early) could be one way to minimize interference drag. Lochte’s arms exiting the water sooner in backstroke may be another way to minimize interference drag. This has not been formally studied yet, however. Other areas for future research include optimizing pull width in breast and fly.”
It is clear, swimming has a lot of room for improvement, not only in technology and evolution (which other sports rely on), but in understanding technical skills and swimming specific training principles ( Is there a Limit on Human Swimming Improvement? . These biomechanical improvements are why large time drops still occur, like the large improvement with underwater dolphin kicking in swim races.
Most recognize biomechanics are the main area of improvement for elite swimmers. Like golf and tennis, swimming is a highly technical skill requiring repetitive, accurate movements for learning. Tennis and golf professionals have coaches helping them with technique. In these sports, a radar gun or mishit ball makes it obvious when a skill is altered, in swimming technical changes are more subtle. It takes continual awareness for refining a stroke which doesn’t happen overnight. This is one of the main principles of motor learning, the principle of specificity. It takes numerous repetitions of an exact movement to make it autonomous. When it becomes autonomous, one is more likely to subconsciously use these skills in a race, a necessity as conscious thought slows down movement.
To improve biomechanics, many coaches use drills, tools, and feedback, but swimmers don’t always respond with these technical adjustments. This is commonly marked up to incompetence, but every coach should believe their swimmer has the mental capacity and motivation.
When the common tools for improving biomechanics don’t work, it is possible one of the other variables (psychology, nutrition, dry-land) may provide the key for improving the limitation. Unfortunately, one confounded variable in the training of swimming may hinder skill acquisition of biomechanical.
A Confounded Variable
Dry-land is a foggy subject in swimming despite the common use. When polled, dry-land was used in ~93% of swimming programs, yet many non-collegiate coaches do not have formal education on this topic, as they simply provide group programs based on their own experiences (Krabak 2013). In college, strength coaches provide most out-of-water conditioning, yet dry-land accounts for ~44% of injuries in this venue (MacFarland 1996) [INSERT DRYLAND INJURY]. Simply put, dry-land is a highly complex topic, which is further complicated by the fitness industry (see Dry-land Mistake: CrossFit for Swimmers). In my opinion, no research studies will be able to quantify the role of dry-land and swimming, as individuality is mandatory. Yet, individuality is seldom practiced during dry-land, although individuality is likely the best method for enhancing skill acquisition in and out of the pool. Now, many people think the solution is performing “swimming-specific” movements during dry-land to acquire skills in the water. Unfortunately, even exercises closely mimicking swimming (like the swim bench) use different cortical pathways than swimming, likely impairing performance (Bulgakova 1987).

Individuality in dry-land is essential for maximizing benefits, just like swimming. Now, there are numerous gaps in the world of predicting injuries and performance, yet, until disproven, one must agree if an athlete does not have a specific skill on land, they are unlikely to perform this task in the water. For example, if a swimmer, doesn’t have the range of motion of the hips to move their feet wide on the breast kick, it is unlikely they could perform this task in the complex medium of water. Biomechanics are not the only inhibitor of success for a swimmer, often times confidence is lacking. Once again, this can be improved with activities in dry-land incorporating mental training! Lastly, conditioning can be improved in dry-land, but keep in mind, the transference of an exercise skill is unlikely to transfer. For example, if you had a swimmer perform a VO2max test on a treadmill or in the pool, the results would greatly differ. Keeping this in mind, why would running (insert any other conditioning) improve swimming capacity endurance (Roels 2005)? A comprehensive dry-land program must be individualized and address a swimmer’s limitations, providing your swimmers the tools to perform the appropriate tasks for proper biomechanics in the water.

In swimming, every movement (except the start and turn) is open-chain. Open-chain exercises simply mean the movement is performed in space. For example, a seated knee extension is an open-chain movement, whereas a squat is a closed-chain movement. Therefore, traditional movement screens for movement dysfunction (like the Functional Movement Screen) are not 100% applicable for swimmers.
Understanding the whole story is important. Once again, swimming has many variables for performance. If one knows the links between these variables, they are more likely to succeed.
To help connect the dots between in-water and out-of-water limitations, the Swimming Troubleshooting Systemwas created. This system is not a dry-land program, but a guide to help create an individualized portion of your dry-land program for improving technical skills. In fact, if anyone claims one book or dry-land program is best for each individual, run away! No tool is possible for providing individualized programs for each swimmer. Just like the pool, the best coaches adapt volume, intensity, and the other variables to each swimmer. This individuality must be used in every aspect of coaching from psychology to dry-land, not just swimming. This complexity may be too much for a coach to handle, as many coaches have administrative or time-consuming coaching schedules. This makes it essential to surround yourself with a team who can fill the gaps in all these complex areas, as knowing everything, for each swimmer is impossible.
Start understanding the links between swimming and dry-land today! Order a copy of the the Swimming Troubleshooting SystemSwimming Troubleshooting System and start understanding the links between in- and out-of-the water training.


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By Dr. G. John Mullen received his Doctorate in Physical Therapy from the University of Southern California and a Bachelor of Science of Health from Purdue University. He is the founder of the Mullen Physical Therapy, the Center of Optimal Restoration, head strength coach at Santa Clara Swim Club, creator of the Swimmer’s Shoulder System, and chief editor of the Swimming Science Research Review.