Over the past few years, most large-chain gyms have begun purchasing various implements that were once seen only in rehabilitation programs. Bosa balls (a half ball with a solid plastic top), stability (or “swiss”) balls, wobble-boards, and the like can be seen lining gym floors.
The idea is that sports are played in an unstable environment, so therefore, training in an unstable environment is more “functional” for sports. And while it may be true that sports are performed in an unstable environment, it is very rare that the ground is actually shifting below athletes’ feet, as seen with instable surface training.
A study performed at the University of Connecticut examined the results of this type of training versus more traditional training paradigms:
Nineteen healthy, trained members (ages 18-23 years) of a National Collegiate Athletic Association Division I collegiate men’s soccer team participated. The experimental (unstable) group supplemented their normal conditioning program with lower-body exercises on inflatable rubber discs; the control (stable) group performed the same exercises on stable surfaces.The stable group improved significantly more than the unstable group in 40-yard sprint time and there was a trend toward greater improvement in the stable group on the 10-yard sprint time. Both groups improved significantly in other areas. These results indicate that unstable training using inflatable rubber discs attenuates performance improvements in healthy, trained athletes.