The American College of Sports Medicines issued the following guidelines for Resistance Exercise (note that this is land-based training):

• Adults should train each major muscle group two or three days each week using a variety of exercises and equipment.
• Very light or light intensity is best for older persons or previously sedentary adults starting exercise.
• Two to four sets of each exercise will help adults improve strength and power.
• For each exercise, 8-12 repetitions improve strength and power, 10-15 repetitions improve strength in middle-age and older persons starting exercise, and 15-20 repetitions improve muscular endurance.
• Adults should wait at least 48 hours between resistance training sessions.

Water has a greater density than air and therefore all directions of submerged movement provide resistance.  If equipment is added, the type of equipment chosen (buoyancy, weighted, rubberized or drag) will affect the overall muscle action, determining which muscles of the pair are actively targeted.  Additionally, the amount of resistance encountered is related to the surface area and shape of the object being moved as well as the velocity of movement.  These factors make the pool a great place to perform resistance training for a wide range of ability levels.

Typically, when we think of strength training in water, we think of working in shallow water.  For example, stabilizing in a squat or lunge position while isolating the upper body, using the water’s resistance alone or adding equipment.  Or, performing squats, lunges and other movement patterns for the lower body. Other options include combination exercises to target functional training goals. The strategies for resistance training in deep water, however, are different because the body is immersed to the neck and suspended off the pool bottom.   Let’s consider some training techniques and deep-water concepts that allow for safe and successful resistance training in deep water.

Always begin with the spine in neutral.  In neutral posture, the segments of the spine are aligned in gentle curves.  The sternum is lifted, the shoulder blades are retracted and down, the abdominals are braced, and the gluteals are contracted to stabilize the pelvis.  The feet are directly below the hips. 

Participants are not always aware when they have deviated from neutral alignment.  Sometimes the upper body leans forward.  At other times, the legs move forward of the body (“driving the car” position.) While traveling laterally, the participant might turn her upper body to face the direction of travel, rather than leading with the side of the body.  All of these positions take the spine out of neutral.  Exercising with poor posture increases the risk for compromising safety.  Additionally, when exercising in neutral posture, you can actually generate more force with your extremities.

A concentric contraction occurs when the muscle generates force while shortening.  An example is the contraction of the biceps when a heavy jug of milk is lifted.  An eccentric contraction occurs when the muscle generates force while lengthening, e.g. the biceps lengthening to slowly lower the heavy jug of milk back to the table.  An isometric contraction occurs when the muscle generates force without changing length; no joint movement occurs – such as holding the jug of milk just off the table’s surface.  Since all movement in water is loaded, actions of both muscles of a muscle pair are resisted when flexing and extending a joint.  Therefore, muscle actions in water are primarily concentric, UNLESS resistance equipment is added to the equation!  Should you choose to add equipment for added resistance, it is imperative to understand how the muscle actions are altered to assure that selected exercises effectively achieve the desired results.

Accelerate at the beginning of the range of motion and decelerate at the end.  Adding power to your movement increases the load on the muscles and leads to improvements in strength.  It is important to know what the normal range of motion is so that you do not risk injury.  For example, the safest end range of motion in shoulder abduction is 70 degrees.  The safest end range of motion for horizontal shoulder abduction is 90 degrees.  The safest end range of motion for hip abduction is 50 degrees. 

When performing resistance exercises for the upper body in deep water, begin with a stabilizing movement of the legs, such as a knee-high jog, a cross-country ski, or a deep-water jack. Some examples of upper body exercises (no resistance equipment) with stabilizing legs are:

* Helpful Hint: move arms in opposition to legs to prevent “bobbing” up and down in the water

When performing resistance exercises for the lower body, begin with a stabilizing scull of the arms, and then add the leg movement.  Some examples (no resistance equipment):

Adding the element of travel can increase exercise intensity. Acceleration of specific movements will propel the body forward, backward or lateral.  Maintain spinal alignment; give posture cues frequently. Pay special attention to the breaststroke, as participants may sweep farther back than the recommended 90-degree range of motion.  This exposes the head of the humerus, increasing the potential for shoulder injury.  Participants also tend to do the breaststroke with thumbs down, but horizontal shoulder abduction with internal rotation can add stress to the shoulder joint, so it is best to perform the breaststroke with thumbs up.

Below are some examples of travel with upper body movements without added resistance equipment. When targeting the upper body with powerful movement patterns, the legs can perform a knee-high jog, which is second nature to most participants.  You may also want to perform these same arm movements from a seated position, which not only concentrates attention on the upper body, but it also adds challenge to the core muscles.  Note that the Lat Press Down and Triceps Press do not assist travel, but instead elevate the body upward during the acceleration phase of the exercise.

For the lower body, focus on powerful leg movement to propel the body through the water.  You can use complementing arm movements, a scull, or hold the arms in a neutral position, such as crossing at the chest or holding behind the back. 

The third step in the progression is to add equipment.  Webbed gloves are the ideal first choice.  Webbed gloves are drag equipment. They increase the surface area of the hand and the drag resistance in all directions.  The muscles primarily contract concentrically with drag equipment, just as without equipment.  (There is a slight eccentric firing of the opposing muscle during the deceleration phase of a movement, allowing the arms to quickly change direction.)  Any of the upper body exercises described above can be performed with webbed gloves.  Webbed gloves will also increase stability with sculling during exercises for the lower body.

Buoyant equipment is popular in deep-water exercise.  With buoyant equipment, such as noodles, foam hand bars or leg cuffs, the resistance occurs when the equipment is moved toward the pool bottom.  The equipment floats to the surface of the water, so upward movement is assisted.  Concentric contractions occur when the equipment is pushed under the water; with a slow and controlled upward movement, an eccentric contraction will occur in the same muscle.  What this means is that only one muscle of a muscle pair will be worked in a specific exercise when utilizing buoyant equipment. 

Specifically, the latissimus, triceps, gluteus maximus and hip adductors are easy to target with buoyant equipment.  It is more challenging to target the deltoids, biceps, Iliopsoas and gluteus medius.  When hand held buoyancy equipment is submerged and then moved parallel to the pool bottom, some drag resistance is encountered by the muscles involved in the movement.  However, the latissimus and lower trapezius must contract isometrically to keep the equipment submerged.  Also, the tendency will be to abduct the shoulders past the recommended range of motion, which can cause joint impingement. Therefore, for safety considerations, limit the amount of time or number of repetitions for these exercise choices.  Also, be sure to relax the shoulders and stretch the fingers between sets when using hand-held buoyancy.  When using buoyant equipment in one hand, hold the other arm at 70 degrees of abduction to help stabilize the body. 

Below are some upper body exercises using buoyant equipment:

Noodles and buoyancy cuffs are often utilized to target the lower body during deep-water training. For example, one foot can be placed on a noodle for a vertical leg press or a hip extension. Some participants may not have the core strength to control the noodle in deep water, in which case leg cuffs are a better choice.  Try some of these leg exercises with buoyant equipment:

Although core training has not been specifically mentioned, if all of the above exercises are performed with good posture, then the core is being trained functionally.

The American College of Sports Medicine recommends that everyone strength train at least twice a week. Strength training prevents age related loss of muscle mass and improves balance. So consider adding an element of cross training with resistance formats – head to deep water for a challenging, safe and effective workout! 

RESOURCES

ACSM. (2011) ACSM Issues New Recommendations on Quantity and Quality of Exercise.

Retrieved February 27, 2013, from American College of Sports Medicine:

AEA. (2010) Aquatic Fitness Professional Manual, Sixth Edition.  Champaign, IL: Human Kinetics

Alexander, Christine (2011) Water Fitness Lesson Plans and Choreography. Champaign, IL: Human Kinetics

Ivens, Pauline, MS & Catherine Holder, PT. (2012) Do No Harm: DVD and Notebook.

                www.aquaaerobics.com

Stuart, Craig. (2002) HYDRO-FIT Deep Definition. Eugene, OR: HYDRO-FIT, Inc.

Christine Alexander is the author of Water Fitness Lesson Plans and Choreography. She is an AEA CEC provider and a member of the Board of the Metroplex Association of Aquatic Professionals in Dallas, Texas. She teaches water fitness classes for the City of Plano Parks & Recreation Department. She holds certifications through AEA, USWFA, YMCA and the Arthritis Foundation.