"Functional? Or foolish"
The following was taken from the Journal of Strength and Conditioning Research, published online February 19th, 2010.
"Most health clubs and fitness programs offer core strength and stability classes. Exercises on unstable surfaces, such as Bosu Balls, Swiss Balls, and wobble boards are central components of most core conditioning programs. Instability is not effective for building the core. An Indiana State University study found no relationship between core strength and performance in functional movement tests. No study has ever found that doing core exercises on unstable surfaces improves athletic performance or builds significant strength in the core muscles. "
"The best exercises for building core strength are large, whole body exercises, such as squats, deadlifts, standing overhead presses, kettlebell swings, and some plyometrics. Ground based exercises have the same force, velocity, and core stabilizing requirements needed in sports and movement skills. Stay grounded for a strong core."
We play sports on stable surfaces. We work on stable surfaces. We live on a stable surface. How many times have your found yourself moving or performing on waterbeds, inflated balls, or wobbly planks? Chances are, not very often if ever. Take movement patterns required to live. Train them with external resistance in something that resembles the environment you live in. Stabilize your midline. Welcome to functional, usable core strength.