Balance Training: Toward a Comprehensive Understanding and Application of the Overload Principle in Motor Skill Acquisition.

The effect of the overload principle in motor skill acquisition is unclear. Hence, the present study examined the effect of the overload principle in general, and in particular how the overload principle can be used to increase transferability to nontrained balance tasks with a high level of similarity at different levels of difficulty. A total of 24 participants were randomly assigned to two training groups: (1) low-difficulty training group and (2) high-difficulty training group. Both training groups completed five training sessions consisting of 25 trials over three weeks and only the level of difficulty of the balance board differed. Both the low and high-difficulty training groups had a significant improvement in balance performance in the specific trained conditions, which supports the specificity principle. Most interestingly, only the high-difficulty training group showed significant positive transfer to balance tasks with lower levels of difficulty. The low difficulty training group did not show significant positive transfer to balance tasks with higher levels of difficulty. These findings support the effect of the overload principle. In conclusion, the present findings demonstrate the superior effect of task-specific balance training, and, most interestingly, the study revealed that training with overload at higher levels of difficulty enhances transferability to similar tasks performed at lower difficulty levels.