INDEPENDENT LOADING RESISTANCE TRAINING IMPROVES NEUROMUSCULAR COORDINATION

Independent loading maximizes the neurological principal of “cross talk” that occurs between the two hemispheres of the brain. It is well known that the right side of the brain controls the left side of the body, and visa versa. It is less well known however, that the two sides of the brain learn from each other as they move (Schulze, K., et al, 2002, Sainburg, R. L. & Wang, J., 2002). This allows each hemisphere to become better at controlling its side of the body. In other words, the left arm learns about moving from the right arm. This is an extremely important concept when considering training using complex or “functional” movements, which require a high level of muscular coordination.

Often, one side of the body is more coordinated than the other. This is because everyone has a dominant side, and that side naturally coordinates movements more easily. When one learns a more difficult exercise, like those movements associated with cable motion machines, it is often difficult initially for the non-dominant side to perform the movement.

However, the non-dominant side can learn the dominant side’s movement pattern by working at the same time. This way the non-dominant side can improve its coordination with a low-load then the weight is progressively increased. At the same time, the dominant limb is getting the workout it needs by having its own load.

BENEFITS FOR INJURY PREVENTION AND REHABILITATION

Working on an independently loaded machine can also assist with the identification and elimination of muscle imbalances that can be masked when working with dependently loaded equipment. If the user is unable to lift the same amount of weight with both limbs, the muscle imbalance is immediately identified. This allows the user to correct the imbalance through training. Without identification of muscle imbalances a user is more at risk for an injury.

Independent loading provides a unique tool for rehabilitation versus traditional dependent loading.

The load on the recovering limb can be reduced, as necessary, to allow for slow progression of weight and safe healing. Strength in the non-injured limb is maintained by utilizing higher loads. Since the limbs can be exercised simultaneously, the time allocated to the resistance training portion of their rehabilitation program can be reduced. This can allow for more time to address other areas of rehabilitation.

INDEPENDENT LOADING ENCOURAGES EFFECTIVE TRAINING

An often used technique of training with dependent loading is when the stronger limb assists the movement of the weaker limb through the range of motion. This helps the weaker limb get in reps at its appropriate load, and can be performed with independent loading, as well. By using just one handle, the stronger limb can physically assist the weaker limb through the range of motion. This increases the length of time it takes to complete the sets and reps.

A more time efficient way to work with limbs that require different loads is to use less weight on  the weaker side so that it can actually do its reps at the same time as the stronger side. If needed, an additional set can be added for the weaker side to promote greater gains and the eventual elimination of the imbalance.

ADDITIONAL BENEFITS OF INDEPENDENT LOADING

Training plateaus and boredom are always a difficult problem for any exerciser to overcome. The  key is to consistently find new ways to stress the muscle so that it is triggered to adapt. There are a couple training options that make independent loading a valuable tool for addressing these issues.

The first option for variety is exercising each limb independently at its maximum weight. Research  has shown that exercising one limb at a time can allow for greater loads to be lifted by the individual limb then when both limbs are activated at the same time. (Cresswell, A. G., Ovendal, A. H., 2002, Hakkinen, K., et. al., 1997) This can increase the stress placed on the muscle and promote greater strength gains.

Another variation is to train the limbs in an alternating fashion. This allows the user to focus on the power and speed of the limb movements as the exerciser rapidly alternates between movements of the two limbs. This will also activate the core muscles to allow for movement as the emphasis is shifted from one side of the body to the other. Alternating the limbs at a slower speed can also be performed by working one limb with the opposite limb stabilized in the extended position (e.g. on a chest press). This would require the core to work more as a stabilizer than a mover.

SUMMARY

Independently loaded selectorized resistance machines are a recent innovation to resistance training, and now are available to a wide audience. These machines allow the user to improve neuromuscular coordination, address limb strength imbalances, reduce the risk of injury, promote rehabilitation, and create a simplified learning environment. In addition, independent loading offers additional programming options to help exercisers overcome plateaus and boredom, make greater strength gains, and promote the use of the core muscles during exercise in a variety of ways.

REFERENCES

Cresswell, A. G., Ovendal, A. H., (2002) Muscle activation and torque development during maximal unilateral and bilateral isokinetic knee extensions. J Sports Med Phys Fitness, 42(1): 19-25.

Hakkinen, K., Kraemer, W. J., Newton, R. U., (1997) Muscle activation and force production during bilateral and unilateral concentric and isometric contractions of the knee extensors in men and women at different ages. Electromyogr Clin Neurophysiol., 37(3):131-142.

Sainburg, R. L., Wang, J., (2002) Interlimb transfer of visuomotor rotations: independence of direction and final position information. Exp Brain Res., 145(4):437-47.

Schulze, K., Luders, E., Jancke, L., (2002) Intermanual transfer in a simple motor task. Cortex., 38(5):805-15.