I’m not really sure why some people think that in order to train their “core” they need to become acrobats on a thera-ball. Skillfully, they balance and twist their way through a workout, looking like Cirque de Soleil clowns. The question is what is effective for building core strength.
Strength and power is about delivering force into the floor. By putting an unstable surface betwen yourself and the floor, you limit the force you can acheive.
Somewhere along ye lines people have been sold on the idea that the core is somehow separate and can be maximally trained on it’s own with a “stability device”. This simply is not he case.
A new study from the journal of strength and conditoning compares core activation of different exercise approaches, and discovers the greatest activation with free weights. Electromyographic(EMG) acitivity of core muscles were measured. Athletes were tested on different equipment.
They concluded that “strength and conditioning specialists should focus on implementing multi-joint free weight exercises, rather than core-specific exercises, in order to adequately train the core muscles in their athletes and clients.”