It wasn’t too long ago that fitness centers and strength and conditioning facilities became equipped with a variety of instability devices such as bosu balls, wobble boards, suspension trainers and so forth. This was because of previous research that demonstrated greater activation of trunk musculature when traditional core exercises were performed on an instability tool.
The predominance of instability device use was also inspired from the field of physical therapy and athletic training. Performing rehabilitation exercises on unstable surfaces provided a means of enhancing proprioception in injured limbs and were quite effective in speeding up the recovery process.
Today, instability devices are widely used and applied in the strength and conditioning setting. However, it is unclear if performing trunk training exercise on unstable surfaces is superior to stable surface training for increasing athletic performance markers in high level athletes. It is clear that core strength is an integral component to sporting movements but which training method is better?
A new study published in the Scandinavian Journal of Medicine and Science in Sports compared stable versus unstable trunk training in high level, teen-aged soccer players. Thirty-nine male soccer players were split into a stable training group and an unstable group. Over a 9 week period, athletes performed between 2-3 core training sessions per week in addition to participating in routine soccer practices. Core training involved various planks (bilateral and unilateral), trunk extension and flexion movements and various derivatives of each. The only difference between the groups was that the unstable group performed the exercises on an instability device. Before and after the training program, performance markers (speed, agility, kicking speed and counter-movement jump) were evaluated.
The results essentially showed no significant differences in performance markers between the stable and unstable core training groups. Therefore, core training, despite whether performed on a stable or unstable surface, appears to be effective in improving trunk strength, sprint and kicking performance in highly training young soccer players. In practice, it would be logical to use unstable surfaces as a progression. Master the movements in stable environments first, then introduce perturbations to stability with various implements.
Prieske, O., Muehlbauer, T., Borde, R., Gube, M., Bruhn, S., Behm, D. G., & Granacher, U. (2015). Neuromuscular and athletic performance following core strength training in elite youth soccer: Role of instability. Scandinavian Journal of Medicine & Science in Sports. Ahead of print.