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DO WATER POLO PLAYERS NEED TO DO STRENGTH TRAINING: PART 2?

Dante Dettamanti BS, MS
Coached Stanford University to Eight NCAA Championships

Volume 1 Number 8 September 1, 2010
Water Polo Doesn't Come with an Instruction Book - That's Why We Have Coaches.
 

Dry-land strength training is part of the conditioning program of many water polo teams around the world, with the idea being that the stronger you are, the better your performance in the water. A big question that we have to ask as coaches, trainers and players-- is strength training necessary to become a better player, or is it just something that has been perpetuated by strength trainers as necessary for all sports? It sounds logical. Get stronger and improve your performance. Is it really that simple? Do the same principals of strength apply in the water as it they do on land? Is the dry-land strength training that many teams do really needed for better performance in the pool?

Gaining strength and power simply for the sake of being stronger or more powerful, is of relatively little importance to athletes unless it also improves their athletic performance. Resistance training for field-event (shot-put, discus, etc) athletes, weight lifters and football players makes intuitive sense; because strength may be the single most important physical factor in success in those events. The need for resistance training by the gymnast, distance runner, swimmer, baseball player, high jumper, water polo player, or ballet dancer is less obvious.

Every sport has a basic strength requirement that must be met to achieve optimal performance. Training beyond their requirements may be unnecessary and costly in terms of time. Perhaps all that is required in terms of strength in a particular sport can be achieved simply by training and participating in that sport? Athletes cannot afford to waste time on activities that won’t result in better athletic performance. To resistance train solely to become stronger, with no associated improvement in performance, is of questionable value.

If we just want water polo players to become bigger in body mass or achieve bigger, stronger muscles, we can accomplish that by having them perform traditional dry-land weight training exercises. However, water polo has unique strength requirements that are different from the mainstream dry-land sport. Most of the differences have to do with the water medium that the water polo athlete performs in. Because of water’s lack of a solid mass that gives an athlete a base of support for application of force, and the effect of buoyancy on the body that negates the force needed to overcome gravity; the need for strength may be much different for the water polo player and the competitive swimmer, than for a land based athlete.

Performing a sport in the water changes everything that we know about performing on land. Why?  Because when a swimmer or water polo player pushes their hand or foot against the water, the water gives way. So, the biggest question we can ask is, if the water gives way when you push on it, how does a swimmer gain propulsion and how does a water polo player gain upward lift? In other words, how is power produced when the medium that you push on (water), gives way when you push on it? More importantly, how much strength (force) does it require to push your hand or foot through the water?

The purpose of this article is to try to answer these questions, and also to answer the most important question of all, is strength training even necessary for success in water polo? Let’s first start by looking at the sport of water polo, and what parts of the game might possibly need added strength for improvement in performance. I can think of four areas where added strength might be of benefit to the water polo player: swimming speed, leg strength (eggbeater) to get higher out of the water, shooting the ball harder, and the grappling and holding that goes on underwater between two players. Swimming relies on pulling the hand and arm through the water to create propulsion. So, we will look at that part of water polo separately.

The other three areas that could possibly require strength for success, the eggbeater, shooting a ball, and wrestling in the water, are all related by one common factor; and that is the ability of the legs to produce force while performing the eggbeater kick. Even though the above skills of swimming and eggbeater involve different parts of the body (the arms and legs), they are similar in that the fluid mechanical principles of lift and drag apply to both the arm pull and the downward kick. Consequently they will be examined together when analyzing the thrust and propulsion that is created when the hands and feet move through the water.

This is the second of a three-part article about strength training for water polo. In Part 1 we analyzed ways in which a swimmer produces power to get the propulsion to move forward in the water in a horizontal position. Part 2 will analyze how a player produces upward propulsion (lift) while performing the eggbeater kick, and then in Part 3 we will analyze whether dry-land strength training can be utilized to increase performance while swimming or while doing the eggbeater kick, and finally answer the question “IS STRENGTH TRAINING NECESSARY FOR INCREASED PERFORMANCE IN WATER POLO”?

First, let us look at the conclusions that we came to in Part 1 about swimming and strength:

1. In looking at forward propulsion, we explained the need of the swimmer to create POWER, the key factor in explaining movement in swimming and water polo. Many people mistakenly confuse power with force or strength. They state that if you have strength, than you also have power. In truth, strength is only one component of power. Speed is the other component. When you multiply strength (force) times speed (velocity), then you have power (Power = force x velocity). Power is necessary to provide movement in all sports. The more force that you can apply, or the more speed that you can apply the force with, the more power you will have. Increase one or the other, or both, and you will gain power.

2. The power formula can be applied to movement in the water as well as on land, except for one important difference. In the water, propulsion cannot be generated by pushing-off from a fixed point, like the runner who pushes off the ground. Instead, in the water, propulsion is the result of pushing-off from water that gives when you push on it. In other words, the mechanical force generated by the muscles on dry land is directly applied to forward motion; while in the water, the force generated is mostly wasted on pushing the water backwards.

3. As the hands push against the water, muscle strength seems to be irrelevant; because most of the force just goes into the water, and does not help that much in propelling the body forward. Pushing back with more force does not help to propel the body forward faster. For this reason alone, we can postulate that it would be an advantage to have stronger muscles (more force) when pushing back against a solid object; while in the same token, there would be little or no obvious advantage to more strength (force) when pushing back on the water.

4. Besides the differences in applying force on land and in the water, there are also differences in the resistance encountered on land and water that will act to slow the athlete down. To run fast or jump higher, the athlete on land has to mainly overcome gravity. On the other hand, to swim fast or get higher in the water, the water polo player needs to be able to generate enough force to overcome drag forces of the water in order to propel the body forward or upward. Because of the buoyant force of the water pushing up on the body, the swimmer does not have to worry about overcoming gravity, only on overcoming drag resistance.

5. So, if applying force in the water is not effective in creating propulsion, how do we create enough power to propel the body forward. Remember, that there are two factors that contribute to power--- force and velocity. So, if one is not effective, increase the other. The swimmer does this by increasing the speed of the arms moving through the water. The faster the swimmer can move the arms (up to a point), the faster the swimmer will move through the water. Compare the faster arm speed of a sprint swimmer to the slower turnover of a long distance swimmer and you can see how this principal works.

6. In the water, the two major components of propulsion are drag and lift; and they both contribute to the movement of the body forward and upward. For many years it was thought that lift (similar to the lift on an airplane wing) was the major contributor to propulsion in swimming. Recent studies, however, indicate that drag makes the major contribution to propulsion while swimming. Although it has never been accurately measured, lift probably plays more of a role in thrusting the body upwards while performing the eggbeater kick; perhaps because of the lift that is also generated from the buoyancy of the water pushing up on the body.

The conclusions of the above discussions on drag and propulsion as it relates to swimming, has been based mostly on applying scientific principals of fluid mechanics. Up until now it has been difficult to collaborate the science with actual research because of the difficulty of measuring force production in the water. In order to measure force produced by the swimmer, a fixed and immovable reference point is needed to get an accurate measurement. Dutch exercise scientist H.M. Toussaint, who has probably done more studies on swim propulsion and drag than anyone in the world, has come up with a way to measure force while swimming by having the swimmer push against a series of paddles from which accurate force measurements can take place.

His latest research using this system in 2007, resulted in a published paper titled “Strength, Power, and Technique of Swimming Performance” that drew the conclusion that “SWIMMING IS NOT A SPORT THAT REQUIRES MUCH STRENGTH TO SWIM FAST”. This collaborates the idea that it doesn’t take a lot of force to overcome the drag of the water, and that a lot of the mechanical force that is produced goes into pushing the water back.

Below Figure 1 illustrates how pulling the hand or pushing the foot through the water can produce drag forces (Fp) that will help propel the swimmer forward or thrust the body upward.

Figure 1
Fig 1: Drag force produced by moving hand and foot through the water.

Figure 2
Fig 2: Lift produced by moving hand and foot through water and moving airplane wing through air.

Above in Figure 2 the lift is produced by moving hand and foot through water and moving an airplane wing through air.
 
In Figure 2  above, lift of the body or the airplane is the result of the flow of the water or air moving past the hand, foot and wing creating less pressure on the top of the hand, foot or wing, than on the bottom. The result is an upward lift on the object (wing and foot) or in the case of the water polo player, moving the body forward or upward.

HOW DOES THE WATER POLO PLAYER INCREASE DRAG AND LIFT?

One way to increase both drag and lift while swimming or using the eggbeater, is to position the hand and the foot so that more surface area is presented to the water, and thus more force created. Positioning the hand and the foot is mostly a matter of correct technique. The water polo player can utilize different methods to keep the bottom of the foot pushing down on the water while performing the eggbeater. Positioning the hand to achieve maximum force is a little more difficult in water polo than in competitive swimming, because of the nature of the water polo swim stroke (less shoulder roll, short and choppy stroke).

So what is the answer to swimming faster or getting higher in the water? Remember that Power = force x velocity. So, if we can’t produce more power in the water by increasing the force component of power, then we have to increase the velocity component. In other words move the arms and the legs faster through the water. Not only does increased velocity help to increase the drag on the arms and legs, but it also increases the lift on the arms and legs. The faster the arm or leg can move, the more of a pressure difference is created between the top and the bottom, resulting in more lift. This is the same as an airplane taking off by going faster and faster down the runway until it lifts up off the ground. If the plane goes too slow, it will not fly.

This is why water polo players must move there arms faster to gain speed and move their legs faster (eggbeater) to gain more height in the water. The drawback to rapid movement of the arms and legs is that this kind of intense movement can only be accomplished for short distances, before the body becomes fatigued. Consequently, this ability to move the arms and legs fast for a short period of time must be trained.

TRAINING TO INCREASE ARM AND LEG SPEED

So how is a player able to move the arms and legs through the water rapidly, and then repeat this fast movement over and over again during a game or practice? The best way is to perform the activity (sprinting and eggbeater) in practice at a high enough intensity that it will stimulate the muscles to improve (contract faster). What we are really training here are the energy systems responsible for supplying energy (ATP) to the  contracting muscles, namely the anaerobic creatine-phosphate (CP) and the anaerobic lactic acid (LA) systems. While performing the activity in practice, the intensity must be high enough to overload the energy systems, so that they will adapt and improve. This cannot be done by slow swimming or easy eggbeater. Only sprint swimming and fast kicking can do this.

STRENGTH CONTRIBUTION TO SPEED?

The only strength that is necessary is the strength required to move the arm through the water. This can be acquired by performing the event in question (i.e. 20 yard all out sprint swim) over and over again. So, the best training in order to swim faster in the game is to practice swimming fast in practice. Any extra strength beyond what is required for sprint swimming is not really necessary for optimum speed perfomance. Only by training the energy systems responsible for sprint swimming can the water polo player achieve the increase in arm speed necessary for optimum performance in a game.

The same principles apply to performing the eggbeater kick. The kick has to be practiced with enough intensity to overload the systems that supply energy to the leg muscles. Training by performing the kick at fast speeds (ie explosive jumps) is necessary. Proper technique in positioning the bottom of the feet is also an important factor in performing a good eggbeater kick.

Heredity plays a big role in performing the eggbeater, because the structure of the knee and ankle joints that you inherent from your parents is what allows the water polo player to properly position the feet and legs for maximum power. As in pulling the arms through the water, applying more force to the kick will not achieve desired results because most of that force goes into pushing the water down. Consequently, leg speed and technique become the most important factors in performing the eggbeater. 

SHOOTING THE BALL

The same leg action that is needed to get high in the water, is also necessary for shooting the ball faster. The legs thrusting downward, commonly called the boost, is one of the key factors to increasing speed of forward shoulder rotation. Proper throwing technique (skill) is important, probably the “most important factor”, in insuring that maximum force is translated from the legs to the arms. Shooting the ball starts from the tips of the toes and finishes from the tips of the fingers. Putting all of the factors together in the correct sequence, and using the proper form, is critical to the success of the shot. 

Arm and shoulder strength is also a factor in throwing or shooting the ball with greater velocity; but it is not as important as you may think. Sometimes take a look at the upper bodies of some of the top major league pitchers. Many of them do not have great upper body strength and are slim with small frames. Major league pitching coaches will tell you that proper form and technique and shoulder and elbow structure are the two most important factors in throwing a baseball. You don’t have to have big or strong arm and shoulder muscles to throw a ball hard!

In water polo, I have observed some of the best shooters in the game over the past 40 years. The players with the strongest legs (eggbeater kick) and the best shooting technique were usually the best shooters on the team. Just as in baseball, the players with the best technique, leg strength, arm velocity, and ability to apply force to generate power are important facets of throwing a ball. Some of the ability to throw a ball may have to do with factors in joint, bone and muscle structure that may have been inherited from your parents. Do not discount heredity as a very important part in success in throwing a ball.

PUSHING, PULLING AND HOLDING- LEVERAGE IN THE WATER

Another area where strength is required in water polo, is the constant wrestling for position (pushing, pulling and holding) that goes on between players at the 2-meter position. Many of these players are physically big and strong; but they would not be successful at their position without a strong eggbeater kick. It is the kick that gives them the platform so that they can apply the upper body strength to gain and hold position in the water.

Do not confuse strength with size and mass. 2-meter players are larger than field players, because bigger size, especially in the upper body, makes it more difficult to get around them. However, if two players that are the same size are grappling with each other in the water, the one with the best legs will win the battle. Think of the 2-meter players as football linemen who are maneuvering against each other. The big massive 350 lb offensive lineman can just stand there and get in the way of the on-rushing smaller defensive lineman. However, if the defensive player has the ability to apply more power by using leg strength and speed, he will win the battle between them; and eventually get to the quarterback.

CONCLUSION

The conclusion that we can come to from the above application of fluid mechanics and power principals to swimming and water polo, is that speed of the arms and legs, and not more strength, are important factors in increasing power for propulsion while swimming and performing the eggbeater kick. These fast movements can only come from training the anaerobic energy systems that contribute to the fast contracting muscles that move the arms and legs rapidly in the water. Increased strength of the muscles from dry land strength training is not necessary to increase the speed of movement. Technique, streamlining, heredity, velocity of arms and legs, and training the anaerobic energy systems, become more important than strength in increasing swim speed and that contribute to a strong eggbeater kick.

In most sports activities, whether on land or in the water, the strength necessary to perform the specific activity can be acquired from simply practicing and participating in the sport itself. So, in order to acquire the strength to play water polo, you need to play water polo, overload the swimming muscles with sprint training, and overload the leg muscles with leg training in the water. More than that amount, as we have shown, does not necessarily result in better performance. Additional strength acquired from dry-land strength training is probably not required to swim faster, or perform the eggbeater kick better in the sport of water polo.

While the above conclusions come from applying physiological and fluid mechanical principals, Part 3 of this article will investigate actual scientific studies that will attempt to show if there is a correlation between dry-land strength training and improvement in swimming speed, height in the water, and shooting velocity.  

[Click Dante's photo to learn more about his water polo experiences and
Click one of the water polo balls to learn where to buy Dante's books.]


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