Water-based aerobic classes follow the same principles of land based exercises with the exceptions noted in this section. Water based exercise is predominantly for lower body exercise in a low impact, resistance based, environment. Although water-based exercise classes began with an emphasis on the elderly, that is no longer the case. You will find participants with varying levels of fitness and the full spectrum of ages in attendance.
Land vs. Water Exercise
The principles of water based training are similar to land-based training; however, the techniques are different. The body is uplifted in water by process called buoyancy and since the viscosity or thickness of the water is greater than air, movement of the body through the water provides an increased level of resistance (drag) over land-based exercise. The buoyancy factor provides support for the body, thereby reducing the likelihood of muscle, bone and joint injuries. Buoyancy is defined as the ability of water to support a body's weight. Items float or are buoyant in water because they displace an amount of water that weighs the same as the item itself. To simplify, an item floats when it displaces its own weight in water. This is why heavy iron ships float and small rocks sink and is subject to size, weight and shape or surface area in contact with the water. It was the ancient Greek mathematician, engineer, physicist, and not the least astronomer Archimedes that first stated this principle and we've been using it ever since. If you can't float in water, at least you now know why.
Muscle is not as buoyant in water as fat. Therefore, both the chest and abdomen provide the greatest buoyancy since this is where air and most body fat is located. This becomes more significant in deep water versus shallow water immersion.
- Reduced impact on joints
- Reduced stress on joints by decreasing weight bearing
- Tones muscles
- Provides resistance in both eccentric (elongation) and concentric (contraction) muscle movements
- Improved balance and posture
- Increases flexibility, reducing capability for injury
- Allows special populations to exercise easily
- Equivalent calorie burn as land-based exercise
Because of the reduced influence of gravity, joints can easily be moved through the full range of motion without excess joint stress helping to improve flexibility. Deep Water-based running exercises can provide an augmented or alternate training regimen for runners who need to reduce the chronic effects of land-based running due to impact injuries.
Since the effects of gravity are reduced in water, impact is reduced while resistance to the movement is increased due to fluid dynamics. A water based class can burn more calories than a comparable land-based class due to the increased resistance to movement while providing an increase in muscle strength and endurance. Both cardiovascular and strength training exercises may be part of an aqua fitness program. Strength gains are not as good as weight bearing exercises on land since the weight is reduced by the buoyancy of the water. The speed of body movements through the water will subsequently be slower due to the increase in resistance. The equivalent level of physical fitness can be accomplished in water-based exercises as with land-based exercises.
Water based exercise reduces body weight by about 90% when immersed to the chest level, and 50% when at waist level which alleviates stress on joints and the supporting tissues. At the same time, resistance is increased by a multiple factor depending on the speed of movement due to water's higher density over air, which is about 800 times greater. Exercise in water has an added advantage that it can provide a user selectable resistance to movements. In addition, water pressure on the legs assists in circulation.
Water based exercise classes provide less joint stress not only for healthy individuals, but also for those special populations affected by medical conditions such as arthritis, neck and back problems, strokes and obesity. This type of aerobics also may be more acceptable for the self-conscious overweight exerciser. Special populations should acquire a medical clearance before beginning any exercise program including water-based-exercises. It is important to note that since gravity is not as much of a factor in water-based exercise; it will not be as effective as land-based exercise in preserving bone density.
Water-based exercise programs should be avoided by individuals who have the following:
- Compromised Respiratory Functions
- Severe Hypotension
- Bladder or vaginal Infections
- Any Infectious Diseases
- Chlorination Allergies
- Open or Unhealed Wounds
In addition, anyone who is apprehensive about being in water or has a fear of drowning should be excluded from water-based exercise programs. The onset of panic can be quite fast and could cause injury. It is important that those individuals who cannot swim be provided with adequate floatation devices.
Aqua Instructor Considerations
Water-based exercise classes may place a greater physical demand on the instructor. Your level of energy expenditure in a water-based environment will certainly depend on how long you are actually instructing while in the water. Chlorinated water, water cleanliness, sunlight (if outdoors) will all provide an additional strain on the instructor over land-based indoor exercise classes. The chlorinated atmosphere can produce an additional strain on the respiratory system and vocal chords of the instructor. This is especially true of the instructor is doing many more classes a week than one would normally attend if just a participant. Since everyone's sensitivities and stamina is different, it will be up to the instructor to determine the maximum number of classes to teach per week to avoid overtraining and environmentally induced abuse.
There are two different styles used in teaching aqua exercise classes with advantages and disadvantages for both. While some instructors will prefer a particular style, it is recommended that a combination of both styles be used to facilitate the demonstration of the exercises as well as reduce the effective water immersion time for the instructor. As in land-based classes, it is also sometimes advantageous for the instructor to move around the class and provide individual coaching. Remember, the class is intended for the participant's exercise time, not the instructor's.
This style provides the best instructional view for the participants with the least amount of effort for the instructor. It also provides the instructor with a better view of the class participants and facilitates shorter learning curve for the class participants. Remember that any move demonstrated should be slowed to simulate the increased resistance of the water. Since participants will be watching the instructor at a higher level, it is important to correct instances of neck hyperextension to avoid excess pressure on the cervical disks. The instructor's position should not be limited to facing the class, but be optimized to facilitate proper instruction.
Instructors should be careful to avoid slipping on slippery decks, which can be minimized by wearing water shoes. Care should also be taken with regard to exposure to heat and humidity to avoid heat exhaustion by drinking plenty of water and occasionally dipping into the pool.
This style provides the instructor with the same exercise medium as the participant allowing easier simulation of exercise moves. However, it makes it difficult for the instructor to demonstrate the moves since the participant cannot see the instructor's body movements. This precludes the ability to demonstrate the moves and their proper form to new or unfamiliar participants. Again, this may be more fun for the instructor; however, this is not the instructor's exercise time. This may be an effective style with seasoned participants as well as for short periods to demonstrate water specific techniques.
The intensity of a particular movement in which air is the only resistance will be less as opposed the same movement through the much denser medium of water. Air, although invisible, is a gaseous substance and provides resistance and thereby friction to an object moving through it. Water can be considered similar to air just denser. This medium provides a type of resistance known as Isokinetic resistance. You will remember from the previous chapter on Kinesiology that Isokinetic exercise is that which is defined as changes in muscle length and tension. Most of the exercise that we encounter in the gym is Isotonic; i.e. changes in muscle length with constant tension (the weight resistance doesn't change). In water, the exercise may be Isotonic or Isokinetic.
As an example, if we move an arm at a constant speed, the tension remains constant (resistance of the water). However, if we change the rate of speed (acceleration) of the arm movement from slower to faster, we also change the tension (water resistance). This occurs in air also, but is quite minimal and, therefore, goes unnoticed. This change in resistance is not only dependent on speed through the water but on surface area of the part moving through the water. Wearing webbed gloves or holding foam dumbbells will also increase the standing resistance; while changing the rate of speed will change the moving resistance.
Additional resistance can be achieved using a downward movement of foam devices, which contain air. This air is directly acted on by the increased pressure as the item moving deeper into the water. This is due to water pressure. An item 2 inches below the surface contains the weight of only 2 inches of water above it while an item 2 feet below the surface experiences the weight of 2 feet of water pressing on it from above. Divers are subjected to much more extreme pressures by having hundreds of feet of water pressing down and all around their body at those depths. Again, it's just not quite as noticeable in a pool, but the forces are the same.
Well, enough of Hydrodynamics. Instructors can utilize this knowledge of speed, direction and depth changes and the corresponding resistance effects to provide both Isotonic as well as Isokinetic exercise water-based programs. So you can see that water-based exercise programs can provide a greater variance of exercise techniques than land-based exercises when properly utilized.
Just as in land-based exercises, it is important to maintain proper form, which includes posture to avoid injury as well as direct the physical movement to the intended muscle systems. Due to the changes in balance due to the forces of the water, care must be taken to avoid hyperextensions of the neck, back and knees to avoid excess pressure on the joints. Our body is used to reacting with gravity in order to maintain balance and coordination. In water, the effects of gravity are reduced, which alters the interpretation of bodily movements and position. This positional mechanism is called Kinesthesia. From the previous chapter on Stretching we explored the Proprioceptive Neuromuscular Facilitation (PNF) feedback mechanism that provides muscle position and balance information. In addition to balance, Kinesthesia is defined as our sensation of positional movement. An inner ear infection from a common cold might affect our PNF, but not our Kinesthesia. In other words, we might still be able to walk, but not with our eyes closed since our PNF has been degraded. These two concepts are still being debated at this writing. Both of these feedback mechanisms are dependent on gravity and weight sensations; which are affected by water suspension.
It will also be necessary to provide balanced and counter-balanced movements. Again, physics plays an important role in water dynamics. With a nod to Newton, every movement results in an equal and opposite movement and is particularly true in when an object or person is suspended in water. Without the full effects of gravity (weight), a backward thrust of a leg will propel a body forward. This works well for swimmers. Care must be taken to counter balance movements to maintain proper balance and alignment. Choose movements based on the reactionary force that will be exhibited in the water and the subsequent effects on balance.
As in land-based exercise programs, the frequency, intensity and duration of the workout will have a direct influence on the derived cardiovascular benefits.
The Intensity progression provides the application of the properties for regulating resistance levels. Intensity can be varied by increasing or decreasing the speed of a movement or the range of motion or the surface area of the body part.
According to Craig and Dvorak (1968), they found that most people at rest will begin to shiver in water temperature of about 75°F - 83°F (24°C - 28°C) while this temperature would be considered comfortable for swimming. So it is important to begin warm up exercises right away to avoid discomfort. If you need to explain procedures to the class, have them engage in some simple arm and leg movements to maintain body heat that will not distract them from your instructions. It is therefore recommended that classes be conducted in water temperature between 75°F - 83°F (24°C - 28°C) or about 80°F (27°C). Temperatures which are above 85°F place an unusual stress on the cardiovascular system and increase the heart rate in an attempt to cool the body. Temperatures colder than 75°F cause a net loss of body heat and can raise blood pressure by restriction blood flow due to vasoconstriction. Actual temperature recommendations vary widely.
According to the Arthritis Foundation, pool temperatures between 83°F and 88°F (28°C - 31°C) are recommended for water exercise. Since it is mostly the older populations that have arthritis, this warmer recommendation may be suitable for older participants who may have more trouble regulating body temperature. Less intensive classes for this group comprised of gentle movements may allow warmer temperatures as well.
The catch here is that older populations may have elevated blood pressure, which may preclude exercising in warmer water. Participants who have untreated low blood pressure or marginal low pressure should be advised not to participate since the warm water will lower the blood pressure further due to vasodilation. This is especially true of hot tub use. The water temperature as well as the class intensity must be targeted for the population. This is also true for land-based classes regarding room temperature and exercise intensity.
Water based exercises may be performed at one of three different levels: Shallow (waist deep), chest to shoulder depth, or deep water. Deep water classes should only be reserved for accomplished swimmers. Water depth at the chest to shoulder level allows the body to be mostly supported by buoyancy and provides water resistance for the body to work against. Shallower water levels provide mostly body weight to work eliminating the added factor of water resistance. Chest to shoulder depth provides support of 80% to 90% of body weight and allows full suspension (feet off the bottom) for various exercises.
It is important to be aware of the depth of the water that you are jumping into. Shallower than expected can cause injury; deeper than expected can result in drowning for a non or marginal swimmer. Participants should be aware of the need for sunscreen if the pool is located outdoors. Never allow participants to dive into the pool.
It is not necessary for participants to be swimmers in order to do water aerobics. Exercises are done in shallow water, which will keep the head above the water. It is important to wear water shoes so that traction on the bottom of the pool is maintained for safety. Should a participant slip and become submerged, the instructor is required to stop the class immediately and assist the person who has fallen. A lifeguard should be present, however, the instructor should be pool guard certified. It is not necessary to be life guard certified. Life guard training is required for open waters. A pool guard certificate is sufficient for indoor or outdoor pools and is available from most colleges and universities.
If movements require full submersion (accomplished swimmers only), goggles should be worn to protect the eyes from chemicals and bacteria present in the pool. Ear plugs may also be necessary to keep the same out of the ears. Swim caps can be used to lessen the effect of pool chemicals on the hair. Chlorine will lighten all body hair if sufficient time is spent in the pool. Showers should be encouraged after class to wash off residues of chlorine since these can irritate the skin causing dryness and itching. If classes are to be conducted in an outdoor pool, make sure that all of the participants apply a water-resistant sunscreen with a SPF of 15 or higher. You, as an instructor, are responsible for all aspects of their safety.
Both abdominal and the gluteus muscles should be kept tight with a neutral spine. This requires hips to be slightly forward with a straight (not arched) back. High jumps out of the water should be avoided except for advanced students at a high fitness level. Any type of prone exercise which causes the head to be hyperextended out of the water should also be avoided.
The instructor should be CPR certified. In addition, the instructor should be Pool Guard certified. It is not necessary to be a lifeguard. Lifeguard certification is generally for open water environments.
Be sure to make an area scan before the participants arrive to insure that there are no hazards that might cause injury. After they arrive, point out possible hazards and inform them of the slippery nature of the wet areas. Inform them of the location of deeper areas of the pool.
Heart rate determinations are not the same for land as for exercise in water. Studies have shown that water-based exercise heart rates are lower during water exercise, yet the same benefits are the same as land-based exercise.
Aqua heart rates are approximately 13% lower. This may lead to concern for some people who may feel that they are not working hard enough using a land based reference. Heart rates will depend on body position in water. When the body is in a vertical position, heart rates will be about 10 beats lower. In the horizontal position, heart rates will be about 17 beats lower. As an example, a land-based training heart rate of 150 bpm would indicate a water based heart rate of about 140 bpm. It is recommended that a 6 second count be used instead of a 10 second count to account for the increased cooling effect of water, which cools four times faster in water than air.
When performing aquatic exercise, be aware that heart rate may not be the best indicator of the intensity of your workout. Studies have shown that persons who participate in both land- and water-based exercise often find their heart rates lower during water exercise, yet they receive the same benefits.
Possible reasons for land-based and water-based heart rate differences are:
- Compression - Hydrostatic pressure on the veins aids in the venous return of blood to the heart.
- Dive Reflex - When the face is submerged in water, a natural process lowers the heart rate and blood pressure. This may even occur in chest high water.
- Gravity - Blood requires less effort to flow back up to the heart.
- Partial Pressure - A gas (oxygen) enters a liquid (blood) more readily under pressure.
- Temperature - Since water has a greater cooling effect on the body, there is less effort required of the heart.
Due to the hydrostatic pressure of water which exerts external pressure on the chest, some participants shallow breathe (top breathing). It is important to recognize that this is occurring and encourage them to execute full breathing to avoid artificially and dangerously increasing the heart rate and blood pressure. Also keep in mind that raising arms high overhead can artificially increase blood pressure and heart rate relative to VO2 requirements.
If your workout will include head submersion, participants will need goggles for eye protection against the harsh chemicals and bacteria present in the water. Eyeglasses or contacts may only be worn if submersion is not part of the routine. Swim caps may be useful not only to keep hair out of the face, but to lessen the effects of pool chemicals on the hair. Never use regular land-based weight in the water. The use of flotation devices to increase buoyancy may help to compensate for reduced natural buoyancy. However, using buoyancy devices below the waist can result in an unstable condition. A user with too much buoyancy at the ankle level may find it difficult to maintain an upright position.
- Water Barbells (Aqua Blocks) - small foam barbells, which increase the resistance as you move your arms through the water.
- Aqua Step - used to perform step aerobics in the water using a special non-skid surface.
- Flotation Belts - attached to waist to provide additional buoyancy allowing you to increase your range of motion and work more muscles.
- Gyro Joggers - two foam rubber circles worn on the wrists or feet to increase water resistance.
- Hand Webs - webbed gloves used to increase water resistance.
- Kickboards - used to provide extra buoyancy allowing you to increase your range of motion and work more muscles.
- Water Noodles (Woggles) - are long cylinders of foam that can provide increased buoyancy and increased resistance.
Water level may be anywhere from waist to chest level for beginners and intermediates and deeper water for experienced participants. For deep water classes, the participants should wear flotation devices. Class level and water depth will depend on the skill level of the participants and the class goals. Equivalent class cadence or music tempo is not going to be the same as the same land-based class due to the resistance of water. The cadence will depend on your participant's fitness level and should be in the range of 125-150 bpm for shallow water exercise. Complex movements are to be performed at a slower tempo or every other beat; while simple movements may be performed at tempo. Keep the volume lower than land-based music to compensate for the increased echo effect in the pool area and so as not to mask the instructor's verbal cues.
Exercises should not be too complex especially for beginners. Demonstrate moves, especially proper weight transfer on deck so it is visible to the participants. Conducting the majority of the class from the deck has two advantages. Primarily, it allows the participants to see and hear you clearly. Secondly, it provides the instructor with a better view of the participants for safety concerns. Remember, this is their workout not yours. Have the participants spread out. More space will be needed for each participant than the 5 x 5 foot area recommended for land-based exercises. For water-based exercises, a larger area of about an eight foot circle (4 ft radius) is needed to accommodate drifting and shifting in the water as well as extended kicks.
A typical class should last about 50 to 60 minutes with a 5 to 10 minute warm up and a similar cool down and stretching period. This will provide a full 30 minute cardio training period. The class should begin with simple moves to allow the participants to become accustomed to the buoyancy of the water.
It is equally important to maintain hydration even in water-based classes. The body continues to perspire, although not as noticeable when it is immersed in water. Thirst triggers may not be as effective when the body is immersed in water. So, it is important to advise the class to bring their water bottles and use them regularly.
Corresponding movements are those where the arm and leg on the same side of the body move together. In opposite movements, the arm on the one side of the body moves in the same direction as the leg on the opposite side of the body.
Double movements are those where both arms move together in the same direction, while in singles, only one arm moves at a time.
- Corresponding - refers to same side as in left arm and left leg
- Opposite - refers to opposite side as in left arm and right leg
- Doubles - refers to opposing arm and leg as in left arm and right leg
- Singles - refers to a single side as in left arm only
The primary focus of water-based exercises is the legs, which contain the largest muscle mass. Moves include kicks, leg extensions, knee lifts, squats, marching and jogging. The first few classes in any workout generally focus on the moves, proper form, and breathing techniques. As the participant becomes more familiar with the class and instructor, they will be able to increase the intensity of the workout. Start moves slowly and then gradually pick up speed. Always land on the ball of the foot and then roll to the heel with entire foot on the floor. It will not be as easy to maintain coordination with the music, so limit each exercise routine to about 25 repetitions.
- Basic Stance - stand with feet facing forward, shoulder width apart and knees relaxed. Arms on hips or at the side
- Bob - jump with both feet simultaneously, knees kept soft
- Boxer - jump twice with the left and then twice with the right foot, knees kept soft
- Bent Leg Jump - jump from one foot to the other and back as in modern dance or ballet
- Cross-Country (Aqua Ski) - Alternate arms and legs in wide opposing movements with tightened glutes
- Frog Jump - keep toes, knees, and legs pointed outward at 30 to 45 degrees, bring knees up while pushing arms down to side
- Heel Lift - jump with heels and knees together while raising heels toward glutes
- Hops - hop forward and back or side to side
- Jumping Jacks (front) - raise alternating knees waist high
- Jumping Jacks (side) - raise legs simultaneously to each side and return
- Lunges - forward or backward keeping both knees soft and toes ahead of the knee, point your toes straight ahead
- Rocking Horse - moving forward and backward with bent knees, forward knee rising to the chest
- Scissor Jump - jump with a move of one leg forward and other back and alternating arms.
- Tuck Jump (Straddle) - elbows flexed, bring both knees up to waist level while lowering arms to sides or perform circles
- Water Jogging (Jogger) - run in place with legs together or wider than shoulder width apart while swinging arms
- Sculling - movement of arms in a side to side and downward waving motion to provide lift
Once you have established the correct stance, a variety of arm and leg movements will be introduced. A complete water aerobics workout is designed to work all of the major muscle groups. Combine a triceps push, biceps curl, shoulder shrugs and other standard arm movements with any of the moves above to extend the variety of the workout. If you are familiar with other activities, you can incorporate those moves into your class such as the jumps used in jumping rope or dance. Cardio Kickboxing moves can also be incorporated into a water-based fitness class. It will be especially important to maintain proper Cardio Kickboxing form to ensure balance. The moves above are only a sample of the moves available. Use you imagination to create stationary as well as travelling moves.
Due to buoyancy, participants may find themselves balancing on their toes. Cue them to press their heels to the floor of the pool to avoid calf cramps (Charlie Horse).
- Participants should be in water to the chest level
- Start with Basic Stance - feet facing forward, shoulder-width apart, knees soft and arms at the side
- Stretch the quadriceps, calf muscles, hip flexors and hamstrings
- Jog and scull in place, knees raised to waist height at low intensity
- Jog around an area of the pool, knees raised to waist height at low intensity
- Perform Lunges - toes pointing forward, either leg extended to the rear with arms extended forward for balance
- Begin an increased intensity portion of the class with Frog, Tuck and Scissor Jumps
- Continue an increased intensity portion of the class with Skiing and Rocking Horse moves
- Begin an decreased intensity portion of the class with Bobbing and Jogging
- Follow with a stretch of the quadriceps, hamstrings, hip flexors and calves