The purpose of this study was to compare the effects of two different types of unstable surface balance training (uniaxial on a rockerboard (RB) and multiaxial on a dynadisc (DD)) on balance in Division 1 collegiate athletes in sports that are high-risk for ankle sprains. Subjects (n = 36) consisted of male soccer players, and female volleyball and soccer players, and were equally and randomly assigned to one of three groups (CON, DD, RB). Balance training consisting of balancing on one leg on either the RB or DD, while repeatedly catching a 1kg ball was performed 3 times per week for 4 weeks. Balance was tested with the Star Excursion Balance Test (SEBT) prior to, halfway through, and at the completion of the balance training. Control (CON) subjects also were given the balance test, but did not participate in the training. A 3-way repeated ANOVA revealed that no group individually changed SEBT scores from pre (CON; 0.98 ± 0.086, DD; 0.98 ± 0.083, RB; 0.97 ± 0.085) to post (CON; 1.00 ± 0.090, DD; 1.01 ± 0.088, RB; 1.02 ± 0.068) following balance training. When the two treatment groups were combined (DD and RB), the P value decreased and came closer to significance (p = 0.136). When all three groups were combined, there was a significant difference in SEBT scores from pretraining (CON + DD + RB; 0.98 ± 0.085) to post training (CON + DD + RB; 1.01 ± 0.082), which likely indicates low statistical power. The increase in physical activity the subjects experienced during the return to in-season activity, may have contributed to the significant differences in SEBT scores over time but not between DD or RB training. Therefore, a threshold level of physical activity may exist that is necessary to maintain balance during the off season.