The ability to optimize muscular power output is considered as a basis for successful performance in the most sports. The aim of this study was to investigate changes in dynamic exercise performance following a sequence of preconditioning isometric muscle actions. Twelve nonathlete, active female volunteers (age: 16±1 yr, height: 162±6.34 cm, weight: 60±9.21 kg) participated in the present study. After the familiarization period (2 weeks), participants underwent one repetition maximum (1 RM) testing for the back squat exercise. Then, subjects participated in two preconditioning protocols at interval of 1 week. First protocol was included 15 minutes warm-up (jogging, active stretch, 5 repetitions back squat with %50 1RM and 2 repetitions back squat with %75 1RM) for preconditioning. Second protocol was included 15 minutes warm-up (jogging, active stretch, 4 repetitions back squat with %50 1RM, 1 repetition back squat with %75 1RM and 1 repetition back squat with %90 1RM) for preconditioning. After each protocol, subjects performed vertical jump, bosco 5, 15, 30 and 60 seconds tests. Paired-samples t-test and independent samples t-test were used to identify any significant differences and statistical significance was set at p< 0.05. Results: In all 5 tests, second protocol had better and significant (p< 0.01) results than first protocol. Percent changes were 19.05, 15.20, 14.58, 11.37 and 11.06 in vertical jump, bosco 5, 15, 30 and 60 seconds tests, respectively. Conclusion: possibly, in performing preconditioning protocols, the higher the intensity, the better the consequent dynamic performance and it seems that the effect of preconditioning protocols reduce over time.