Aquatic Resistance Training
As obesity rates rise, exercise professionals are faced with the challenge of improving fitness levels for overweight individuals safely. Water exercise offers intensity, variety, and safety for the educated trainer to use with this population.
Convincing overweight clients to add resistance training can sometimes be difficult. Adding to this difficultly is the fact that most resistance-exercise machines are designed for nonoverweight individuals, meaning that overweight clients may not fit into the machine, or may have trouble aligning their joints with the pivot point of the machine. Further, free-weight exercises that require the use of benches or stools may not be comfortable or safe, again because the equipment may be too small for larger individuals.
One solution is to perform resistance training in the water. Performing resistance exercises in the water means that there are no machines to squeeze into and no heavy weights involved. Instead of using gravity and weight to create resistance, the client uses buoyancy, water resistance, and drag to increase his or her workload. Resistance in the form of increased drag can be varied through the use of webbed gloves, tubing, and plastic or foam buoys. Even without water-based equipment, just the density of water adds more resistance to moving your limbs than moving through air.
One way that moving in the water increases intensity is through inertia. When you move forward in the water, the water also moves forward. When you reverse the body's direction, the water keeps moving, making you work against the current you have created until you have again caused the water to move in the same direction as you are moving. Related to inertia, acceleration also increases intensity. You can increase the resistance by increasing the movement speed and the time it takes to reach that speed. In order to reach higher intensities in a workout, the client should apply more effort in doing a movement under the water.
Buoyancy decreases the effects of gravity and reduces weight bearing or compression on joints. It is dependent upon the depth of immersion—being more immersed displaces more water and increases buoyancy. At neck level, body weight is reduced 90%; at chest level, it is reduced 65–75%; and at waist level, 50%. Buoyancy affects movement in the water in other ways—assisting upward movements and resisting downward movements. Pushing buoyant equipment, such as foam tubing, down into the water adds to the intensity of the workout.
Drag is another force impacting on water exercise. Drag is that force that opposes movement in the water, and is affected by surface area, velocity, and the shape of objects moving in the water. The position of the arm (extended or flexed), the position of the hand (cupped hand vs. flat hand), the speed of movement, and the use of equipment can increase or decrease drag. Using water buoys, for example, helps to increase drag by increasing the surface area and shape of the hand moving through water.
Exercising in the water utilizes the large muscle groups in a supported, nonimpact environment. Most important, working in the water requires clients to focus on developing core strength to help correct the imbalances that have resulted from orthopedic and weight-related issues. Water exercise requires individuals to use their core muscles for stability. Higher body fat results in higher buoyancy, and that buoyancy challenges a person's stability in the water. In order to remain vertical and in good posture, clients must constantly activate their back and abdominal muscles. The pressure applied by the water on the core muscles also activates these muscles constantly.
Moving in the water can reduce the awkwardness that obese clients face when exercising in the gym. Because of the buoyancy and support of the water, clients can work without concern for balance or for falling down
. The water allows clients to exercise safely, concentrate on their form, and focus on the feel of the activity. Being in the water allows every individual to work at his or her own level of exertion without the limitations of size or weight.
The benefits of water exercise are many—it reduces the effects of edema, combats blood pooling, and enhances the flow of blood to muscles and the flow of lactates from muscles. Other benefits are lower heart rate compared to land-based exercise (approximately 7–12 beats·min−1 slower); slower, deeper breathing; and increased muscle relaxation. For these reasons, water is a supportive and safe environment for the obese client.
Brian Housle is an Exercise Physiologist and Head Personal Trainer with the Duke University Hospital System in their Diet and Fitness Center
Original article found on www.nsca-lift.org