Aqua Notes - The Race Club

The Dynamics of Dolphin Kick Part I: Using the Vortex

The Dynamics of Dolphin Kick Part I: Using the Vortex

The two sources of propulsion we use while swimming, the hands and the feet, work in different environments. Although the hands and feet are creating nearly all of the propulsion in the water, the flow dynamics where the forces are taking place for each one differ considerably.

In order to produce propulsion, the surface areas creating the forces (from the hands and feet) must move backwards relative to the water. The hands begin to create propulsion when they are about one foot in front of the shoulder. Since the hand is in front of and to the side of the body when the pulling propulsion begins, the vortex created by the body does not affect the water where the hand is pulling until the end of the pulling motion. In other words, the hand is pushing backward against relatively still water during the times it is producing most of the propulsion. Not so with the feet.

Behind every swimmer moving forward is a vortex of water (wake) created by the separation of the water moving along the body (as the body moves forward). This vortex creates a stream of water that follows the swimmer. It is this stream that enables a swimmer to swim right behind another swimmer and catch a ride. The bigger and the faster the swimmer, the bigger the vortex and the faster the stream is moving. The wake behind a swimmer extends for a few feet behind him and funnels out wider from the feet, but it does not extend very deep in the water. The width of the stream even enables a swimmer that is swimming in the next lane, yet close enough to the swimmer, to catch some of the ride. The most famous example of that was Jason Lezak riding Alain Bernard’s wake as long as he could in the 4 x100 free relay in Beijing, completing the fastest relay leg in history.

Since the propulsion from the feet is occurring, for the most part, within this stream, the stream affects the dynamics of the kicking motion. Relative to a stationary point in the pool, the feet in the dolphin kick (while the swimmer is on the stomach) are moving backward only during the beginning of the down kick. There is virtually no backward motion of the feet at all during the up kick. Yet the feet can create propulsion on both the down and the up kicks. The reason is that the feet need to be moving backward relative to the water only, and since the water is moving forward, propulsion can occur when the feet are moving upward or downward, in addition to backward.

The dynamics of the kick are made even more complicated by another smaller vortex that forms behind the feet as they move across the stream of the body’s vortex. Since most of the motion of the foot is upward, downward or forward, the vortex of the moving foot, somewhat like a tributary connecting to a river, contributes to the fluid dynamics of the body’s stream, generally adding more water moving forward behind the swimmer.

Using the velocity meter technology at The Race Club, from the changes of the body’s velocity and acceleration resulting from each of the down or up kicks, one can gain an appreciation for the amount of propulsive force generated by the foot moving in each direction. With the swimmer on his stomach, the down kick, which involves extension of the knee and flexion of the hip, is a biomechanically stronger motion than the motion of the up kick, which involves extension of the hip and flexion of the knee. Further, with the extraordinary plantar flexibility of the ankle of a fast kicker, the surface area of the foot moving backward relative to the water is greater on the down kick (top of the foot) than it is during the up kick (sole of the foot).

In the gym, for example, I can lift about 70 pounds 50 times before exhaustion on the down kick motion. However, using the up kick motion, I can lift 30 pounds for about 30 reps before exhaustion. The difference would suggest that the down kick motion is at least twice as powerful as the up kick motion. Therefore, when analyzing the velocity and acceleration of the swimmer’s body while dolphin kicking, one would expect to see the greatest acceleration and peak velocity occur from the down kick, rather than from the up kick. While a swimmer is on his stomach that is precisely what one sees. However, the difference in speed resulting from the down kick and the up kick on the stomach will surprise you.

In the next article, we will examine in detail the acceleration, velocity and differences between peak and trough velocities resulting from the dolphin kick performed on the stomach, side and on the back.

Yours in swimming,

Gary Sr.

Read Dynamics of Dolphin Kick Part II: Why Dolphin is Faster on Your Back

Pictured is Olympian Junya Koga from Japan.

The Art of Breathing in Swimming Part III

In part II of this series, we discussed where and how to breathe in freestyle and butterfly, but the question that remains is ‘how often should we breathe in swimming’? In the first article we established that, for the most part, swimmers train hypoxically. In other words, they don’t breathe quite as often as they would if they could breathe at will. Further, we know that depriving swimmers of oxygen by training at altitude significantly improves all of the aerobic systems involved in the production of ATP. While training hypoxically may make sense for most swimmers, racing hypoxically in any event other than a 50-meter sprint does not. After about 20 seconds of near maximal exertion, we must rely on both aerobic and anaerobic systems of energy production to keep going. Bring on the oxygen!

Since the respiratory rate that seems to work most efficiently on land during maximal exercise is 50-60 breaths per minute, we must assume that the ideal respiratory rate for a swimmer racing should be similar. In freestyle, if we consider that breathing every cycle (every other stroke) is the most often we can breathe, then a stroke rate of at least 100 is needed to achieve that respiratory rate. In shoulder-driven freestyle, that is often the stroke rate we see among elite swimmers in the 100 freestyle. The hybrid freestylers, such as Phelps, Lochte or Lezak, may drop down to the mid 80’s, leading to a respiratory rate lower than the ideal.

In the 1500 meter freestyle, particularly on the men’s side, we find an interesting variety of freestyle techniques with substantially different stroke and respiratory rates. World record holder Sun Yang uses a hip-driven technique with a stroke rate of 60 for most of the race. If he used a conventional one-breath per cycle breathing pattern and without considering the turns, that would mean a very low respiratory rate of 30 per minute, but he doesn’t. In the middle of most laps and going into and out of each turn, Sun Yang takes a breath to each side in succession, breathing three or even four strokes in a row. Those extra three or four breaths per length likely have a huge impact on his ability to sustain his speed and finish faster than any other swimmer in the race.

Comparing Sun Yang’s breaths in the 1500 to Ryan Cochrane from Canada, who uses a shoulder driven freestyle technique with a stroke rate of 86, here is what we find. Ryan breathes every third stroke for the first 800 meters or so, then switches to every cycle for the final 700 meters. So for approximately half of the race, Ryan’s respiratory rate is around 28 and for the other half it is 43. If we consider the race to be 15 minutes of duration, that means that Ryan would be getting around 532 breaths. With four extra breaths per length, Sun Yang would be getting around 570 breaths, even with a stroke rate of 60 compared to Ryan’s 86.

Connor Jaeger and Katie Ledecky both swim the 1500 with a hybrid technique and a similar stroke rate of around 86, breathing every cycle. Over 15 minutes of sustained swimming at this rate, they each would have around 645 breaths, more than Sun Yang or Ryan Cochrane.

I am not sure what conclusion we can draw from this, except that both Sun Yang and Ryan Cochrane modify their traditional breathing patterns in order to get more oxygen delivery. Perhaps in the future, we will see more swimmers modify their breathing patterns to get more oxygen delivery by breathing to both sides or abandoning the 1:3 pattern of breathing like Ryan begins the race with.

In the butterfly, there is a growing trend, particularly on the men’s side, toward breathing every stroke for both the 100 and 200 meter events. In the 100 meters, with stroke rates typically in the mid 50’s, that would be very close to the ideal respiratory rate. In the 200, with stroke rates usually in the mid to high 40’s, the respiratory rate breathing every stroke is less than ideal, but not far from it. However, if one breathes every other stroke in fly, in either event, the respiratory rate drops down into the 20’s, which is far from ideal.

It is no wonder that the fastest finishers in the fly are typically the swimmers breathing every stroke. The key points to breathing more are to practice the breathing pattern to be used in races often, develop the ability to get the breath quickly and with the least amount of disruption to the stroke cycle or increase in frontal drag, and to use the kinetic energy of the head drop or head turn as a coupling motion to augment the propulsive forces of the hands and feet. The last point is really what I call ‘using your head’.

Remember, oxygen is the most important nutrient we have, so I say, ‘Let’s get more of it, not less’. Besides that, it is lot more fun to pass people at the end of a race, rather than being the one who is passed.

Yours in swimming,

Gary Sr.

Summer Swim Camp Los Angeles

Come join us for our Los Angeles Summer Swim Camp! 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
July 9th 9:30am -11:30am – Science of Swimming – Reducing Frontal Drag – Freestyle technique
July 9th 2pm-4pm – Race Club mobility routine – Increasing Propulsion – Freestyle technique
July 10th 9:30am-11:30am – Nutrition – Conforming to the Law of Inertia – Freestyle
July 10th 2pm-4pm – Yoga – Progression to a Fast Backstroke
July 11th 8am-10am – Strength training – Key Points to Improve Breaststroke
July 11th 2pm-4pm – Starts – Race Club Swim Strength Circuit
July 12th 8am-10am – Mental training – Developing an Easier and Faster Butterfly
July 12th 2pm-4pm – Race Practice and Strategy
ENHANCED SESSIONS
July 9th 11:30am-12:30pm Breathing Technique and Breathing Patterns
July 10th 11:30am-12:30pm Dolphin Kick Technique and Drills
July 11th 10am-11am Back to Breast Transition Turn
July 12th 10am-11am Starts and Turns
Pricing:
-All 8 camp sessions plus 4 enhanced sessions = \$1300 (\$300 savings if you register by June 8th, 2016)
-All 8 camp sessions = \$1000 (\$200 savings if you register by June 8th, 2016)
-Each camp session is \$150
-Each enhanced session is \$100
*The schedule may vary slightly, depending on who is at the summer swim camp. We try to cater to each swimmer’s specific needs.
Location: Pacific Palisades High School, 15777 Bowdoin Street, Pacific Palisades, CA 90272
We recommend finding an apartment or house to rent in the Pacific Palisades neighborhood near the pool. Otherwise there are many hotels in Santa Monica. Email for questions. Or Register Here.

Labor Day Swim Camp

Come join us for our Labor Day 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 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
September 2nd 8am-10am – Science of Swimming – Reducing Frontal Drag – Freestyle technique
September 2nd 3pm-5pm – Race Club mobility routine – Increasing Propulsion – Freestyle technique
September 3rd 10am-12noon – Nutrition – Conforming to the Law of Inertia – Freestyle
September 3rd 3pm-5pm – Yoga – Progression to a Fast Backstroke
September 4th 10am-12noon – Strength training – Key Points to Improve Breaststroke
September 4th 3pm-5pm – Starts – Race Club Circuit Swim Strength Training
September 5th 8am-10am – Mental training – Developing an Easier and Faster Butterfly
September 5th 3pm-5pm – Race Practice and Strategy
ENHANCED SESSIONS
September 2nd 10am-11am Breathing Technique and Breathing Patterns
September 3rd 12noon-1pm Dolphin Kick Technique and Drills
September 4th 12noon-1pm Back to Breast Transition Turn
September 5th 10am-11am Starts and Turns
Pricing:
-All 8 camp sessions plus 4 enhanced sessions = \$1300 (\$300 savings if you register by August 1st, 2016)
-All 8 camp sessions = \$1000 (\$200 savings if you register by August 1st, 2016)
-Each camp session is \$150
-Each enhanced session is \$100
Location: 87000 Overseas Hwy, Islamorada, FL. Email for questions. Or Register Here.

Swimisodes – Dolphin Kick Backstroke

Dolphin kick backstroke is one of the best ways to learn how to develop a fast stroke rate. Many swimmers struggle in getting their arms through the stroke cycle fast enough in backstroke. It is difficult to know how to maintain that high stroke rate throughout a race if it is not practiced so we like to use the dolphin kick backstroke drill to learn how to maintain a high stroke rate. Synchronizing each kick with a single arm pull, Junya shows us how this technique enables a swimmer to pull faster and increase the overall speed of the backstroke. In this Race Club #swimisodes, you will see how Junya still manages to rotate his body quickly from side to side while pulling at this higher stroke rate, gaining power and speed.

There are only two stroke rates for backstroke, fast and faster. Dolphin kick backstroke drill is a wonderful technique to develop a faster stroke rate. Swimmers who cannot find a way to turn their arms over quickly might discover a faster way to swim with dolphin kick backstroke. Introduce fins using this technique while synchronizing the arms and suddenly the swimmer is backstroking on the freeway, motoring down the pool. At the Race Club, we have found this technique to be very effective in improving backstroke among swimmers who come to us of all ages and abilities.

How to Inhale and Exhale While Swimming Fast

The Art of Breathing Part II – How to Inhale & Exhale While Swimming Fast

First, I want to dispel one myth about breathing during intense exercise. In no sport does an athlete ever take a complete inhalation or expiration. The breaths during intense exercise are relatively quick and shallow, meaning that a little O2 comes in and a little CO2 goes out with each breath. It is an air exchange, not a deep breath.

The most detrimental part of breathing in swimming is likely not the associated increase in frontal drag, though that can be significant, depending on how the breath is taken, but rather the slowing of the stroke rate. Particularly in shorter races, a long, ‘star-gazing’ breath that slows the stroke rate can have disastrous consequences for both speed and inertia. To help with stroke rate and frontal drag, getting the breath quickly and with the least amount of change in body position is vital. In freestyle, that means turning the head minimally (keeping one goggle lens in the water during the breath), elevating the mouth to one side to meet the air, and rotating the head posteriorly (backward) rather than straight to the side or forward. In butterfly, it means extending the neck forward maximally for the breath, keeping the mouth close to the water, while maintaining the body in a more horizontal position. Or in cases where swimmers can’t seem to avoid lifting the shoulders too high for the front breath, breathing to the side in butterfly may be a better option.

While in land-based sports, the inhalations are immediately followed by expirations and vice versa, or, in other words, there is no ‘breath holding’, in swimming, there may be a theoretical advantage in doing so. On land, our weight does not change appreciably with each breath, but in the water it does. The weight of a swimmer ranges from zero with the lungs inflated to around 8 lbs (4kg) after a maximal expiration (there is always some residual volume of air in the lungs). The buoyancy of the human body also goes from neutral to negative after expiration. The question is, do we hold the air in our lungs for as long as possible after putting our face back in the water, then exhaling with a quick burst prior to capturing the next breath? Or, do we do as the Red Cross teachers told us to do as children, trickle the air out of our nose or mouth, prior to the next breath?

The changes in body weight and buoyancy can impact frontal drag of a swimmer, particularly while swimming on the surface. The higher the swimmer can be on the surface, the less frontal drag and the faster the swimmer can go. A swimmer is faster in salt water, where there is more buoyancy, than in fresh water. The density of water is so great that just a few millimeters of difference in body position on the surface can have a significant impact on a swimmer’s speed. So, it would seem logical that swimmers would want to keep the air in the lungs as long as possible, weigh less, be more buoyant and burst the air out of their lungs at the last moment, before turning the head for the breath.

But that is not what great swimmers do. Katie Ledecky, Sun Yang, Grant Hackett, Ian Thorpe, Michael Phelps and virtually all of the other great freestylers release some air through the nose immediately upon planting their faces back in the water after the breath. The great butterflyers of the world do the same. With the speed of their bodies moving forward, those air bubbles from the nose move underneath their bodies before finding their way to the surface. The rest of the exhalation comes just before and while the head is turning or elevating for the next breath. In that manner, the inhalation can begin immediately once the mouth reaches air, so the head can return promptly to the face down position without slowing the stroke rate.

I did not recognize the significance of those bubbles until one of my swimming colleagues at the pool in Islamorada, Florida brought the Emperor Penguins to my attention. The Emperor Penguins of the Antarctic Ocean have evolved to develop a unique way of swimming faster in order to escape the wrath of the hungry seals chasing them. Under the plumes of their feathers, they manage to trap air bubbles. When the seals are chasing the penguins for lunch, the penguins release the air from under the feathers and gain a significant amount of speed, presumably while kicking with the same amount of force with their webbed feet. By releasing the air bubbles, surrounding themselves with air instead of water, they effectively lower their frontal drag forces, which enables them to spurt forward out of harm’s way.

Could it be that the air bubbles under the swimmer’s body released after the breath do the same to a lesser degree? Perhaps. What I do know is that great swimmers usually do the right thing, whether they understand the reason for doing so or not. Releasing some air through the nose after the breath may just be another example of that. So that is what I do and recommend others do.

In the upcoming third and final article of this series, we will examine the most controversial breathing topic of all and that is how often to breathe.

Yours in swimming,

Gary Sr.

Read How Oxygen Affects Our Bodies in a Swim Race: The Art of Breathing Part I

Read Oxygen! How Often Should I Breathe in Swimming?: The Art of Breathing Part III

Alex and Cameron Craft

1 Comment

Hi Amy.
As our first visit with you at The Race Club comes to a close tomorrow, we want to thank you, Abby and your Dad for the superb training that you have provided to our sons, Alex and Cameron.
They have had the time of their lives, and I simply have to share an experience from this afternoon that Mark and I will never ever forget…nor will Alex.
Your dad worked with the kids on breast stroke this afternoon and although it has always been absolutely Alex’s weakest stroke, Coach Hall got him on track and awakened the breast stroker in our son. After years of thinking he just wasn’t ever going to be very good at the stroke, something clicked, and your dad gave Alex the technical skills and confidence to believe in himself; it was a major “aha” moment and Alex is absolutely on a breast stroke high this evening!
For Mark and I to witness this transformation firsthand, we can only say that we are floored, amazed, impressed, and astounded at Coach Hall’s expertise.
I guess that is why we are here, but I just want to let all of you know that you have met and exceeded our expectations and only wish tomorrow morning was not our last session!!!
Before he went to bed, Alex said that Coach Hall changed his life today and that he really learned a lot  about himself and his sport.
As swim parents, you are undoubtedly aware how much our lives revolve around the pool (we wouldn’t have it any other way). We dearly love our boys and to see Alex and Cameron so happy, proud and confident with their newly learned skill sets, makes us happy beyond belief…..All that, and they had a great time too!!!
With Respect and Gratitude,
Mark and Trish Craft

The Art of Breathing Part I – Swim Race

Breathing while swimming seems like a natural thing to do. After all, we do it all the time without even thinking about it and, if we stop doing it, we cannot survive for more than about 7 minutes. Yet, while swimming, breathing is not that simple. The questions ‘How often do we breathe?’ ‘Where do we breathe?’ or even ‘How do we breathe?’ are legitimate ones. The answers are not that obvious, either.

Breathing in swimming freestyle or butterfly can be problematic. It can slow the stroke rate, if one takes too long to get the breath. It can lead to an increase in frontal drag, if the breath causes an alteration in the pulling motion of the arm under water, or if the head lifts too much for the breath. Yet, in any race lasting longer than about 20 seconds, the delivery of oxygen to the muscles, in order to provide an important source of energy, is vital to our ability to sustain speed. In other words, we have to breathe to keep our pace.

The fastest way to swim fly and free is without breathing. Unfortunately, in any race event over a 50 sprint, not breathing enough leads to a catastrophic dependence on anaerobic sources of energy, which leads quickly to a lowering of the body’s pH (H+ ions). Once the body begins to become acidic, the muscles cease to recover or function at the same rate. In swimming vernacular, we ‘die’ in our races.

Perhaps the fastest way to increase the body’s pH, to restore neutrality, is by breathing. The faster the respiratory rate, the more CO2 we blow off in order to increase our body’s pH. Frequent breathing during intense exercise not only helps to maintain a neutral pH, but it also helps prevent the acidosis to begin with by delivering more oxygen to the muscles. Having a pipeline flow of oxygen delivered to the muscles engaged in the activity is essential to high performance swimming. Increasing the stroke volume of the heart, increasing the numbers of red blood cells, improving the transport systems for delivering oxygen to the muscle cells, increasing the numbers of mitochondria in the muscle cells available to convert glucose into ATP (Adenosine triphosphate, the fuel for our muscles), and increasing the number and type of muscle fibers available for contraction are all important parts of the physiological and anatomical improvements we seek from training. Yet, even if we develop those systems, none of them are optimized if we don’t have a nice flow of oxygen arriving at the alveoli of our lungs, ready to be delivered to the muscle.

After the first 20 seconds or so of our race, when we have used up the most readily available and stored sources of high-energy phosphate (Creatine phosphate), the two systems of producing ATP on an ongoing basis are the aerobic (with oxygen) and the anaerobic (without oxygen) systems. The two systems are needed and work simultaneously during intense exercise to produce the kind of power required to swim very fast. While the aerobic system produces more ATP per molecule of glucose than the anaerobic system (approximately 36 moles of ATP vs 2 moles of ATP), the anaerobic system produces ATP faster than the aerobic system. In this respect, they each may have their advantage, yet only the anaerobic system will lower our body’s pH, leading to a dysfunction of muscular contraction. The more we can utilize our aerobic system of producing ATP, the longer we can sustain our power.

If you compare the respiratory rates of swimmers racing with competing athletes from other sports, like running or cycling, where they can breathe at will, the rates of swimmers are usually slower. At maximum effort on land, the respiratory rate of an athlete is typically 50-60 breaths per minute. Rarely is a swimmer breathing that often, either in a race or in practice. One can make the argument that swimmers train hypoxically most of the time, which means that by under delivering oxygen to the lungs, swimmers are developing all of the other body’s mechanisms to deliver oxygen more efficiently to our muscles and to manage lactate production. By training at altitude, where even less oxygen gets delivered to the muscles, one can build all of those mechanisms even better and faster. That is a good thing. But when it comes to racing, other than in the 50 sprints, do we want to race hypoxically? I think not. I can still recall the pain of swimming the 400 IM at the Olympic Games of Mexico City (7,000 feet) in a time about 10 seconds slower than I would have swum at sea level. At altitude, we may not have the choice of getting as much as oxygen as we need, but at sea level, it makes less sense to deprive ourselves of getting that oxygen. That means swimmers should be breathing more, not less.

Next time, we will discuss the how and where of breathing in freestyle and fly.

Yours in swimming,

Gary Sr.

Swimisodes – Backstroke Kick

Getting the backstroke kick right can be very challenging. In this installment of #swimisodes, World Champion Junya Koga first shows you what a typical backstroke kick technique with too much knee bend looks like, causing an increase in the frontal drag slowing you down. Then, using an elastic band above the knee, Junya demonstrates a more correct and faster technique of backstroke kick using less knee bend and a lot of power derived from the hip flexors and relaxed, loose ankles. To kick properly and to avoid the temptation of over bending the knee to get more power out of each kick, Junya and Olympic champion Roland Schoemann demonstrate two important dryland exercises that help increase the flexibility of the ankle. Achieving such flexibility with loose and relaxed ankles is one key qualities needed to develop a faster backstroke and freestyle kick with a tighter, narrower kick.
We use the Finis Ankle Strap in a variety of ways at our Race Club camps to improve kicking technique. When you first try using the elastic band you may get frustrated by the slower speed of your kick. Be patient and continue to work on ankle flexibility with this narrower technique of kicking. Eventually you will see your kicking speed and, more importantly, your backstroke speed begin to increase. Using the flick kick and freestyle kick dryland exercises, you can see great improvement in your ankle flexibility occurring within weeks. The technique of kicking with less knee bend takes time and practice to perfect.

Purchase the Finis Ankle Strap here