The aim of the study was to determine the effect of progressive one-leg dynamic balance training programme on dynamic stability in healthy male athletes.Mixed design with repeated measures at baseline and after 2 and 4 weeks of progressive single-leg balance training.Clinic and gymnasium.Thirty healthy male athletes volunteered to participate in this study and were randomly assigned to a training or control (CON) group.Dynamic stability was assessed using the Star Excursion Balance Test (SEBT) in the trained (TRD) and untrained (UTD) legs in the training group as well as in one leg of the CON group.SEBT scores did not change in the CON leg but significantly increased at 2 and 4 weeks in the TRD leg for total combined score and in all individual directions by ca. 11–36%. For example, in the posterior direction reach increased from 97±6cm at baseline to 112±9cm and 121±7cm (P<0.01) after 2 and 4 weeks, respectively. Performance in the UTD leg increased significantly in 4 out of 8 reach directions to a smaller extent than the TRD leg.A progressive single-leg dynamic balance exercise programme can improve dynamic stability very rapidly. This has practical implications for sporting scenarios such as pre-season training.