In many respects, functional strength training should be thought of in terms of a continued movement. As humans, we perform a wide range of movement activities, such as walking, jogging, running, sprinting, jumping, lifting, pushing, pulling, bending, twisting, turning, standing, starting, stopping, climbing and lunging.
Simply stated, the primary goal of functional training is to transfer the improvements in strength achieved in one movement to enhancing the performance of another movement by affecting the entire neuromuscular system.
In functional training, it is as critical to train the specific movement as it is to train the muscles involved in the actual movement. The brain, which controls muscular movement, thinks in terms of whole motions, not individual muscles.
Exercises that isolate joints and muscles are training muscles, not movements, which results in less functional improvement. For example, squats will have a greater "transfer effect" on improving an individual's ability to rise from a sofa than knee extensions.
The exercises with the highest transfer effect are those that are essentially similar to the actual movement or activity. It is important to note, however, that individuals cannot become expert at a particular movement or activity by training only with similar movements. For optimal results, repeated practice of the precise movement is required.
Exercises performed on most traditional machines tend to be on the low-end of the functional-training continuum because they isolate muscles in a stabilized, controlled environment. While it may be true that traditional, machine-based exercises are not the best way to transfer performance from the weight room to the real world, it does not mean that such exercises should not be a part of a training program.
For example, "non-functional," single-joint exercise can play a critical role in helping to strengthen a "weak link" that a person may have to restore proper muscle balance. Furthermore, doing such an exercise can allow an individual to more safely and effectively participate in functional-training activities while also reducing the risk of injury.
In the final analysis, it must be remembered that functional training is not an all-or-nothing conclusion. Functional strength training should serve as a supplement to traditional strength training, not as a replacement.
Properly applied, functional strength training may provide exercise variety and additional training benefits that more directly transfer improvements to real-life activities.