Aqua Notes

Improving Your Start from the Block – Fast Swimming Starts

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Part II Coupling Motions: The Head

With either type of track start, there are three important coupling motions that will augment the forces of the swimmer leaving the block and result in a better dive. A coupling motion is a movement of some part of the swimmer’s body that produces no propulsive force by itself, yet increases the forces that create propulsion. The three coupling motions are the head lifting up, the arm motion and the back leg lift for fast swimming starts.

The adult head weighs approximately 12 pounds, so if one moves it around quickly, it can create quite a bit of energy. In martial arts, students learn to use their head as a weapon. It can also become a weapon for the start, if used properly.

The energy that the head provides on the start is related to the square of the speed at which it is lifted. If a swimmer takes his mark with the head extended forward, there is little room to further lift it and less kinetic energy that can be attained from its motion. Further, in the extended position, the swimmer is less relaxed, as the neck muscles are working to maintain that position.

Head Motion

At the sound of the starter’s beep, the head should be in the neutral position (looking down) and snapped upward to full extension as quickly as possible simultaneously with the push off of the block with the feet. This motion also helps project the swimmer forward. If the head is held in the neutral or down position, not only does the swimmer lose out on the coupling motion of the head lift, but he also tends to go downward toward the water, rather than forward.

Of course, once the head is fully extended, it must be immediately fully flexed back down, so that the chin is touching the chest, enabling the arms to get into the streamline position behind the head. With practice, there is enough time on the dive to lift the head fully, and then press the chin back down to the chest, prior to entering the water. How much are you using your head to add to your propulsion on your start?

Yours in Swimming,

Gary Sr.

Read Improving Your Start from the Block – Part I:Track Starts

Read Improving Your Start from the Block – Part III: Coupling Motions, The Arm Recovery

Read Improving Your Start from the Block – Part IV: Coupling Motions, The Leg Motion

Read Improving Your Start from the Block – Part V: Five Techniques to a Great Start


The Race Club is Hiring Swim Coaches

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The Race Club, with locations in the amazing tropical paradise of Islamorada in the Florida Keys and in Coronado, a beautiful island in San Diego, is hiring for staff coaching positions ranging from 3 month internships to Senior Staff and Site Directors for experienced, professional coaches and everything in between. Currently we are looking to hire a lead coach based in San Diego, CA.

The Race Club’s Primary Focus is on Swimming Technique and the Technical aspects of swimming. This non-traditional coaching position emphasizes teaching and the science of swimming where the coaching staff is expected to have or develop technical expertise and be on the cutting edge in the sport. This is a great opportunity to launch your coaching career to the next level by learning from world-renowned coaches and world-class athletes while applying proven fundamental progressions to a diverse population of swimmers.

Our Coaches must have a passion for swimming, curiosity and a likable personality with the ability to communicate positively and effectively with others. Swimming experience and success counts, however, all experience levels of coaches will be considered. Applicants should have talents, skills, experience and/or education outside the sport that effectively demonstrate intellect and capacity to learn. Specific skills in computer science, social media, technology, graphic arts, marketing and business administration are particularly valuable.

Benefits. Every day on the pool deck as a Race Club Coach is a step into the lab to learn at the highest level in the sport, develop and practice your coaching skills, both technical and interactive. Off of the deck, you will have the ability to contribute to building the preeminent swimming organization in the world. Opportunities for significant additional income, international exposure, and growth in a dynamic leader in the sport will be available for the best members of our staff. We are also a leader in swimming social media and online delivery of services, making a coaching position with the Race Club one of the most technologically innovative opportunities for coaches in the sport.

Join the Family. If you, or someone you know, is interested in this unique opportunity of coaching/teaching positions, please contact us. Email your resume to info@theraceclub.com.


Improving Your Start from the Block – Track Starts

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Part I Track Starts

Nearly all swimmers today use a track start with one foot forward and the other back on the starting block. With the introduction of the back wedge on the top of the block in 2009, virtually all swimmers adopted the track start. Regardless of the type of start used, the favorable angle of the back wedge increases the potential force from the feet using the track start. The only swimmers that I do not recommend using the track start are older Masters swimmers that have trouble with balance and equilibrium. They are better off with both feet forward on the edge of the block.

There are two distinctly different types of track start, weight forward and weight back (or slingshot). With the weight forward start, the majority of the swimmer’s weight is placed on the front foot with the toes wrapped over the edge of the block. With the weight back start, at the command of ‘take your mark’, the swimmer shifts the majority of the body weight to the back foot by leaning backward a few degrees. In watching the Olympic Games in Rio, there appear to be a significant number of swimmers using both types of track start, weight forward and backward. Here are the advantages and disadvantages of each type.

Weight Forward

Advantages

  • Faster reaction time to get off the block quicker
  • Enables fast dolphin kickers to get in the water sooner

 

Disadvantage

  • Less propulsive force generated with nearly all force derived from front foot

 

Weight Back

Advantages

  • Potential for more propulsion from arms, back and front foot
  • May increase the coupling energy from the arm motion

 

Disadvantage

  • Slower reaction time to get off the block

 

With the weight forward start, most of the propulsion is coming from the front foot and since the weight is positioned further forward, it is the fastest way to leave the block. The center of the body’s mass is positioned directly over the hands which are either pulling upward on the front of the block or the bars on the top of the block. From that position, it is impossible to generate any meaningful propulsion from the arms. It is the front foot (leg) doing most of the propulsion, with some coming from the back foot.

With the weight back start, it is important that the body does not shift backward too far, which would require too much time for the swimmer to leave the block. Only a few degrees of motion are needed to shift the majority of weight to the back foot. From that position, with the center of mass behind the hands, one can generate some propulsion from the arms, with the hands wrapped around the front of the block or on the bars above the block, by pulling the body forward. The propulsion begins with the arms and the back foot simultaneously, then shifts to the front foot as the body moves forward. With the weight back start, there are three potential sources of propulsion, back foot, front foot and arms (hands), while with the weight forward start, the front foot does most of the work.

Deciding which track start to use is not easy. The outcome of either start, however, should not be judged by the reaction time to leave the block, but rather where the swimmer breaks out from under the water. This is influenced by the time required to leave the block, the propulsive force leaving the block (vertical leap ability), the frontal drag caused from arms, body, legs and feet upon the water entry, the mass (weight) of the swimmer, the speed of the underwater dolphin kick and the frontal drag and transitional speed at breakout.

In general, the weight forward start may be preferred by swimmers with exceptionally fast dolphin kicks, as it will enable the swimmer to enter the water sooner. The weight-back start is often preferred by swimmers that have strong upper bodies and arms, and with a bigger vertical leap (more fast twitch muscles). In order to overcome the disadvantage of the delay in leaving the block with the weight-back start, one must take advantage of using the forces from the arms and both feet.

The question of which foot goes forward is controversial. I have found that most swimmers prefer to place the dominant foot forward. Yet I have also seen some excellent swimmers that did the opposite. What is most important is that the swimmer feels comfortable in the selected position of the feet and that it results in the best start.

Regardless of which track start is used, weight forward or backward, both dives should incorporate the three coupling motions to augment the swimmer’s propulsive forces leaving the block. The three coupling motions of the start are the head lift, the arm motion and the upward kick of the rear leg. The amount of kinetic energy in those three motions can have a huge impact on the effectiveness of the dive. In the next article, we will discuss those three important coupling motions.

Yours in swimming,

Gary Sr.

Read Improving Your Start from the Block – Part II: Coupling Motions, The Head

Read Improving Your Start from the Block – Part III: Coupling Motions, The Arm Recovery

Read Improving Your Start from the Block – Part IV: Coupling Motions, The Leg Motion

Read Improving Your Start from the Block – Part V: Five Techniques to a Great Start


Holiday Swim Camp December 17, 2016 – January 2nd, 2017

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Come join us for our Holiday Swim Camp in Islamorada, FL! Below are the details of each session. You can sign up for as many sessions as you’d like, but most swimmers do as many as they can in the time they are here. Some swimmers stay for the entire camp and it’s not repetitive information. Lots of Great material to cover! These sessions are for any swimmer that wants to swim faster. We have had swimmers and triathletes from age 7- 86 ranging in abilities from beginner wanting to learn a flip turn or a stroke, to Olympians. Sign up and we hope you’ll have a great time!
Dec 17th 8am-10am – Fundamentals of Fast Swimming – Reducing Frontal Drag – Freestyle technique
Dec 17th 10am-11am = Enhanced Session – Breathing Techniques
Dec 17th 2pm-4pm – Race Club mobility routine – Increasing Propulsion – Freestyle technique
Dec 18th 8am-10am – Nutrition – Conforming to the Law of Inertia – Freestyle
Dec 18th 10am-11am = Enhanced session – Dolphin Kick Techniques
Dec 18th 2pm-4pm – Yoga – Progression to a Fast Backstroke
Dec 19th 8am-10am – Strength training – Key Points to Improve Breaststroke
Dec 19th 10am-11am = Enhanced Session – Progression of Back to Breast Transition Turn
Dec 19th 2pm-4pm – Starts – Race Club Circuit Swim Strength Training
Dec 20th 8am-10am – Mental training – Developing an Easier and Faster Butterfly
Dec 20th 10am-11am = Enhanced Session – Starts or Turns
Dec 20th 2pm-4pm – Race Practice and Strategy
Dec 21st 8am-10am – Science of Swimming – Reducing Frontal Drag – Freestyle Body Positions
Dec 21st 10am-11am = Enhanced Session – Breathing Patterns, Training and Race Plans
Dec 21st 2pm-4pm – Race Club mobility routine – Increasing Propulsion – Freestyle Underwater Pull
Dec 22nd 8am-10am – Nutrition – Conforming to the Law of Inertia – Freestyle Stroke Rate and Kick
Dec 22nd 10am-11am = Enhanced Session – Dolphin Kick Training or Turns
Dec 22nd 2pm-4pm – Yoga – Backstroke Strategies and Techniques
Dec 23rd 8am-10am – Strength training – Breaststroke Strategies and Techniques
Dec 23rd 10am-11am = Enhanced Session – Back to Breast Transition Turn
Dec 23rd 2pm-4pm – Starts – Race Club Circuit Swim Strength Training
Dec 24th 8am-10am – Mental training – Developing an Easier and Faster Butterfly
Dec 26th 8am-10am – Science of Swimming – Reducing Frontal Drag – Freestyle technique
Dec 26th 1pm-2pm = Enhanced Session – Breathing Techniques
Dec 26th 2pm-4pm – Race Club mobility routine – Increasing Propulsion – Freestyle technique
Dec 27th 8am-10am – Nutrition – Conforming to the Law of Inertia – Freestyle
Dec 27th 1pm-2pm = Enhanced Session – Dolphin Kick Technique
Dec 27th 2pm-4pm – Yoga – Progression to a Fast Backstroke
Dec 28th 8am-10am – Strength training – Key Points to Improve Breaststroke
Dec 28th 1pm-2pm = Enhanced Session – Back to Breast Transition Turn
Dec 28th 2pm-4pm – Starts – Race Club Circuit Swim Strength Training
Dec 29th 8am-10am – Mental training – Developing an Easier and Faster Butterfly
Dec 29th 1pm-2pm = Enhanced Session – Starts or Turns
Dec 29th 2pm-4pm – Race Practice and Strategy
Dec 30th 8am-10am – Science of Swimming – Reducing Frontal Drag – Freestyle Body Positions
Dec 30th 1pm-2pm = Enhanced Session – Breathing Patterns and Training and Race Plans
Dec 30th 2pm-4pm – Race Club mobility routine – Increasing Propulsion – Freestyle Underwater Pull
Dec 31st 8am-10am – Nutrition – Conforming to the Law of Inertia – Freestyle Stroke Rate and Kick
Dec 31st 1pm-2pm = Enhanced Session – Dolphin Kick Practice or Turns
Dec 31st 2pm-4pm – Yoga – Fast Backstroke Strategies and Techniques
Jan 1st 8am-10am – Strength training – Breaststroke Strategies and Techniques
Jan 1st 1pm-2pm = Enhanced Session – Back to Breast Transition Turn or Turns
Jan 1st 2pm-4pm – Starts – Race Club Circuit Swim Strength Training
Jan 2nd 8am-10am – Mental training – Practicing a Faster Butterfly
Jan 2nd 1pm-2pm = Enhanced Session – Starts or Turns
Jan 2nd 2pm-4pm – Race Practice and Strategy
 
*The content of the sessions are subject to change depending on who is signed up for the sessions, weather, or other factors.
Pricing for Holiday Swim Camp:
-Each camp session is $150
-Each enhanced session is $100
There are no discounts at this camp. 
Location: 87000 Overseas Hwy, Islamorada, FL. Email for questions. Or Register Here.

Coronado Swim Camp October 7-10, 2016

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Come join us for our Columbus Day Coronado Swim Camp in Coronado, CA! Below are the details of each session. You can sign up for as many sessions as you’d like, but you can see why we encourage you to sign up for all 8 sessions and the enhanced sessions. Lots of Great material to cover! These sessions are for any swimmer that wants to swim faster. We have had swimmers and triathletes from age 7- 86 ranging in abilities from beginner wanting to learn a flip turn or a stroke, to Olympians. Sign up and we hope you’ll have a great time!
CAMP SESSIONS
October 7th 8am-10am – Science of Swimming – Reducing Frontal Drag – Freestyle technique
October 7th 3pm-5pm – Race Club mobility routine – Increasing Propulsion – Freestyle technique
October 8th 8am-10am – Nutrition – Conforming to the Law of Inertia – Freestyle
October 8th 3pm-5pm – Yoga – Progression to a Fast Backstroke
October 9th 8am-10am – Strength training – Key Points to Improve Breaststroke
October 9th 3pm-5pm – Starts – Race Club Circuit Swim Strength Training
October 10th 8am-10am – Mental training – Developing an Easier and Faster Butterfly
October 10th 3pm-5pm – Race Practice and Strategy
ENHANCED SESSIONS
October 7th 10am-11am Breathing Technique and Breathing Patterns
October 8th 10am-11am Dolphin Kick Technique and Drills
October 9th 10am-11am Back to Breast Transition Turn
October 10th 10am-11am Starts and Turns
Pricing:
-All 8 camp sessions plus 4 enhanced sessions = $1300 ($300 savings if you register by September 7th, 2016)
-Each camp session is $150
-Each enhanced session is $100
Location: Coronado High School Brian Bent Memorial Aquatic Center, 818 Sixth Street, Coronado, CA 92118. Email for questions. Or Register Here for our Coronado Swim Camp.

The Race Club expands to Coronado, CA for their California Swim Camps

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The Race Club, one of the world’s leading organizations teaching advanced swimming techniques, will relocate their California swim camps location from Los Angeles to San Diego beginning July 19th, 2016. The Race Club was responsible for training 53 Olympic swimmers that won 23 Olympic medals over 4 successive Olympic Games from 1996 to 2008. Since then, they have shared their knowledge and expertise by teaching swimming technique and training to swimmers and triathletes of all ages and abilities from around the world attending their camps or private instruction. The Race Club offers the most advanced technology available for improving swimming skills.

Coronado, California is an island in San Diego and home of a United States Naval Base and the west coast training site for the US Navy Seals.  It is a beautiful location surrounded by the Pacific Ocean and San Diego bay. With two Olympic pools within minutes of each other and easy access to many hotels, including the famous Hotel del Coronado, and restaurants, pristine beaches and open water, Coronado is the perfect destination for a Race Club Camp.In addition, just minutes away from Coronado are are several major attractions in the San Diego area including the San Diego Zoo and Safari Park, SeaWorld, Legoland and La Jolla. With year round moderate temperatures that have been called the most ‘comfortable climate in America’, the entire family will enjoy their experience in Coronado.

“It is hard to duplicate the beautiful setting and access to Olympic pools that we have in Islamorada, Florida, but we think Coronado will be its equal in California” says Gary Hall Sr., co-founder and Director of The Race Club. “Coronado is as accessible from the west coast of the United States as Islamorada is from the East. Also, with the Race Club’s global market of swimmers, Islamorada is easier to reach from Europe, while Coronado will be easier to reach from Asia. Both locations are easily accessible from Central and South America”.

Dr. Hall will be splitting his time teaching stroke technique between Islamorada and Coronado, but Race Club coaches and the most advanced technology will be available in both locations for camps and private instruction all year long.  Coronado, known for it’s aquatic lifestyle, with a rich tradition of producing outstanding water polo players, has welcomed The Race Club into its community.

The Race Club will be utilizing Coronado High School Brian Bent Memorial Aquatic Center and City of Coronado Aquatics Center pools to conduct private sessions and our California swim camps.

 

 

For more information or to register to attend private sessions or camps in Coronado, contact us: info@theraceclub.com P: 310-936-1888


Thanksgiving Swim Camp Islamorada, FL

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Come join us for our Thanksgiving Swim Camp in Islamorada, FL! Below are the details of each session. You can sign up for as many sessions as you’d like, but you can see why we encourage you to sign up for all 10 sessions and the enhanced sessions. Lots of Great material to cover! These sessions are for any swimmer that wants to swim faster. We have had swimmers and triathletes from age 7- 86 ranging in abilities from beginner wanting to learn a flip turn or a stroke, to Olympians. Sign up and we hope you’ll have a great time!
CAMP SESSIONS
November 22nd 8am-10am – Science of Swimming talk – Reducing Frontal Drag – Freestyle technique
November 22nd 3pm-5pm – Race Club mobility routine – Increasing Propulsion – Freestyle technique
November 23rd 8am-10am – Nutrition talk – Conforming to the Law of Inertia – Freestyle
November 23rd 2pm-4pm – Yoga – Progression to a Fast Backstroke
November 24th 8am-10am – Race Club Olympics Day! The only day of the year where we have special events for the whole family
November 24th 3pm-5pm – Yoga on the beach – Open Water Swim
November 25th 8am-10am – Strength training talk – Key Points to Improve Breaststroke
November 25th 3pm-5pm – Starts – Race Club Circuit Swim Strength Training
November 26th 8am-10am – Mental training talk – Developing an Easier and Faster Butterfly
November 26th 2:45pm-4:45pm – Race Day! Race Practice and Strategy
ENHANCED SESSIONS
November 22nd 10am-11am Breathing Technique and Breathing Patterns
November 23rd 10am-11am Dolphin Kick Technique and Drills
November 25th 10am-11am Back to Breast Transition Turn
November 26th 10am-11am Starts and Turns
Pricing:
-Each camp session is $150
-Each enhanced session is $100
-All 10 camp sessions plus 4 enhanced sessions = $1600 ($300 savings if you register before October 21st, 2016)
Location: 87000 Overseas Hwy, Islamorada, FL. Email for questions. Or Register Here.

Why the Late Front Breath in Butterfly Makes Sense

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When children learn to swim butterfly for the first time, they often take a late breath in butterfly, pausing their arms at the end of the underwater pull before recovering the arms and taking the breath. We usually try to teach young swimmers to take the breath earlier in the underwater pull to avoid the delay in the arm recovery. While developing a faster pulling stroke rate is important in building a strong butterfly, it may be that the children have it right in delaying their breath.

Two of the fastest butterflyers in the world today, Joseph Schooling of Singapore and Chad Le Clos of South Africa, have a delayed front breath, though they achieve it in slightly different ways. Schooling initiates the head lift later in the underwater pull, while Le Clos holds the head up above water longer before dropping it down. In either case, the head snaps down later than when the front breath is taken earlier in the stroke.

The rationale for the late or delayed front breath has to do with the powerful coupling motions of the butterfly, which include the arms swinging forward during the recovery, the head snapping down and the shoulders/upper body pressing down. None of these motions provide any propulsive force, yet if timed correctly, they can add a tremendous amount of force to the second down kick in the fly cycle. The first down kick occurs when the hands are well into the propulsive phase underwater. The second down kick should be timed with the point of maximum kinetic energy of the coupling motions; when the hands, head and shoulders strike the water on their way down or forward. With the traditional early-breath fly technique, the head is already down before the second down kick occurs, contributing little or no coupling energy to this propulsive force. Similarly, the side breath contributes little or no energy to this second kick. Not so with the delayed front breathing technique.

Nothing is more demonstrative of the power of the coupling motions in butterfly than in the 2015 World University Games 200 finals of the 200-meter butterfly, where Japanese swimmer, Yuya Yajima, won a silver medal in the time of 1:55.7. What was unusual about this swim is that Yuya did that time with a stroke rate of 31, when everyone else in the race swam with a more typical stroke rate of in the high 40’s. Before that race, I would have bet my house that no one could swim a 200-meter fly in 1:55 with a stroke rate of 31. Thankfully, I didn’t.

Yuya’s technique, which has been called the ‘dolphin dive butterfly’, could accomplish that speed only through the use of a strong kick, great streamlining and powerful coupling motions. With the breath on each stroke, Yuya elevates high out of the water, arching the back (similar to breaststroke). Then he swings the arms forward aggressively, snapping the head and pressing the upper body down into a tight streamline, timing the arrival of all three at the surface of the water precisely with the second down kick. The hands are then held in front long enough to take the first dolphin down kick in this streamlined position. The result is an extraordinary surge forward underwater that enables him to be competitive with the other swimmers using a much higher stroke rate.

Neither Schooling nor Le Clos slow their stroke rates, yet by delaying the head snapping and the body pressing downward, they delay the peak of energy from those coupling motions to occur precisely with the second down kick. That leads to a greater surge forward under water after the kick. This technique is similar to the hybrid freestyle, where the swimmer with a strong kick can compete against faster stroke rates by increasing the coupling energy of the body rotation, head drop and faster arm recovery after the breath, leading to a surge forward under water.

Since all fast butterflyers have strong kicks, it makes the use of the delayed or prolonged front breath a plausible technique and worth trying. While in the 50-meter sprint, it is clearly faster to not breathe, for the 100 meters or longer, getting as much oxygen as possible is beneficial. Taking it later in the pulling cycle, rather than earlier, may just be best way to swim fly. Turns out, we may learn something from watching children starting to swim butterfly.

Yours in swimming,

Gary Sr.


Develop a Turbocharged Engine for your Freestyle

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Strong Freestyle 6 Beat Kick 

My wife drives an Audi Q5 that has a 4-cylinder engine with a turbocharged engine. I like the car because if I drive it conservatively, it gets really good gas mileage. Yet, if I need to pass someone quickly on the freeway, by pressing the accelerator hard, the car shifts into a much more powerful mode and picks up speed right away. Of course, it uses a lot more gasoline when I do that, but it is nice to know that I have that option when I need it.

One can look at the freestyle kick as being similar to the turbocharged engine. In the 50 meter sprint, every swimmer needs to push the accelerator all the way to the floor, maximizing the power of the kick all of the way. But in any event longer than 50 meters, one has to back off the accelerator some in order to keep from running out of gas. The longer the swim, the more careful one needs to be about pushing the legs into turbocharged mode. In the mile, for example, that mode is often reserved for the finish of the race. It is the turbocharged mode of the kick that enables Sun Yang to swim the last 50 meters in under 26 seconds, or Chris Swanson from U of Penn to swim the last 50 yards in 24.3 seconds and demolish the field. In fact, whenever there is a close race at the finish, I will always bet on the swimmer who has the turbocharged engine available in his/her legs.

The question is, ‘how does one develop a freestyle with the turbocharge option’? I have focused many of my articles and blogs on the importance of developing a strong kick, but the truth is, it is not easy to do. It requires developing extraordinary plantar flexibility of the ankle, leg strength for both the down and up kick motions, working both sides of the leg, and leg fitness; lots of it.

When you consider your pulling stroke rate, which may vary between 60 and 100 strokes per minute for any distance over 50 meters, with a 6 beat kick, the kicking stroke rate is 6 times that, or 360-600 kicks per minute. That means that during each stroke cycle, hand entry to hand entry, each leg takes 3 down kicks and 3 up kicks. Now consider that your 6 beat kick never really has any recovery time, as the legs are either pushing down or pulling upward at all times. That is a lot of sustained effort. It is no wonder that we cannot keep our legs in turbocharged mode for more than 50 meters without reaching exhaustion. If we are to use our legs in turbocharged mode for any part of the race, however, they simply must be extraordinarily fit; even more so than than our arms are.

Once you develop the turbocharge capacity in your freestyle kick by gaining ankle flexibility, leg strength and fitness, you must also learn how far down to push the accelerator for each race, and when to push the pedal all the way to the metal. The muscles of the leg are big and strong and if you use the turbocharged mode too early or too long, the lactate produced by this mode will ultimately shut you down.

Build a better swimming engine; one with a turbocharge capacity. Do so by working your legs incessantly, in and out of the water, developing the right tools for kicking propulsion. Then plan your longer races carefully, using the 4 cylinders at the beginning, getting good gas mileage, and saving the turbocharge option for the right time at the end. Then you can finish the race blowing by everyone, just like Sun Yang or Chris Swanson. It is a great feeling.

Yours in swimming,

Gary Sr.

 


The Dynamics of Dolphin Kick Part II: Why Dolphin is Faster on the Back

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The Dynamics of Dolphin Kick Part II: Why Dolphin is Faster on the Back

Using The Race Club’s Velocity Meter technology, I analyze the dolphin kick of world champion backstroker, Junya Koga. While on his stomach, he generates acceleration of about .7 m/sec2 on the up kick and 14 m/sec2 on the down kick, a significantly greater difference than one would expect on the basis of strength alone. The up kick results in a peak velocity of about 1.5 m/sec while the down kick results in a peak velocity of over 2 m/sec. However, like acceleration, a better representation of the power of the kicks is the difference between trough and peak velocities from both the up and down kicks (Delta PT). For the up kick, the delta PT is a trivial .1 m/sec and for the down kick, it is around .8 m/sec, also a significantly greater difference than one would expect based purely on strength.

When Junya dolphin kicks on his back, we find an extremely different velocity curve. Now, on the up kick, the stronger motion, we find a peak acceleration of around 3 m/sec2, while on the weaker down kick, we find an acceleration of around 5 m/sec2. The peak velocities of the down kick are also greater than the up kick, 2.1 m/sec compared to 1.9 m/sec. The delta PT is still greater on the up kick, but not by much, .4 m/sec compared to .35 m/sec. All of this suggests that the propulsion from the weaker down kick while dolphin kicking on the back is about the same or greater than the propulsion of the stronger up kick.

With the vast difference in biomechanical strength between these two motions, how can this be? It cannot be explained by a difference frontal drag, since the body positions are very similar. One coach, Rick Madge has proposed that the differences in power comparing the up kick and down kick while kicking on the back versus the stomach can be attributed to gravitational force. I don’t agree.

While gravity still applies in water, the actual force in water, reflected by our body weight, is considerably different. While the legs have negative buoyancy, they probably weigh only a few pounds in the water. That is not enough to affect our ability to kick up or down in water. I believe the differences observed on the velocity meter studies from front to back can be attributed to the vortices formed behind the body and feet of the swimmer.

When Junya is on his stomach, the down kick begins with the knees bent and the feet pushing back against the stream of water moving forward behind the body. The result from this strong motion against a current of water results in an extraordinarily strong surge of power and speed forward; more than one would expect from just the biomechanics.

With the up kick, the feet begin the upward movement below the stream from the body’s vortex and do not produce any meaningful propulsion until they enter the stream. By that time, the amount of propulsion is significantly less than that provided by the down kick. However, a strong upward and forward movement of the feet will create another vortex that will contribute to the stream and result in a greater force with the following down kick.

While on his back, Junya’s up kick begins with the feet below the stream and consequently, the feet do not produce as much force as when they are pushing against the stream. Again, the up kick will add even more power to the stream from the stronger vortex following the feet. When he begins the weaker down kick, he is now pushing against a substantial forward movement of water, almost as if he were pushing against a wall. As a result, there is a greater surge of velocity after the down kick than one would expect from this motion.

While all of these differing vortices may change the fluid mechanics of the kick, the important question is, which way is faster? In this particular study, Junya’s average dolphin kick speed on his stomach was 1.76 m/sec. On his back, it was 1.81 m/sec. .05 m/sec difference may not seem like much, but on an underwater kick off a start or turn lasting five seconds, that is 10 inches further ahead or behind that the swimmer would be; enough to win or lose a race.

I suspect that the difference in a swimmer’s speed from stomach to back has more to do with the law of inertia than to any difference in biomechanical strength or frontal drag. The lower delta PT on the back simply means that the kick is more efficient than while kicking on the stomach, since the swimmer maintains a more constant speed.

For completeness sake, we also tested Junya on his side and found that the velocity curves are similar to the ones on his stomach. The average velocity was measured at 1.71 m/sec, slightly slower than on the stomach, so there does not appear to be any clear benefit to kicking on one’s side compared to the stomach. Since the rules preclude us from remaining on our backs dolphin kicking during the underwater portion of a freestyle or fly race, we cannot recommend using this technique on any race other than the backstroke.

Ryan Lochte and other great backstrokers have figured out that they can kick dolphin kick faster on their backs than on their stomachs or sides. Now we know why.

Yours in swimming,

Gary Sr.

Read The Dynamics of Dolphin Kick Part I: Using the Vortex

Come to The Race Club and get Velocity Meter test done for yourself.

dynamics of dolphin