The Comparison of Unilateral and Bilateral Training Effect to Changes in Speed and Speed-Strength Abilities in Preadolescence Athletes

Abstract

Introduction: The aim of the study was to compare the effectiveness of unilateral and bilateral training program on changes in the level of speed and speed-strength abilities. Methods: Experimental group 1 (EG1) consisted of 8 young athletes (age = 12.76±1.55 years) and experimental group 2 (EG2) consisted of 8 athletes (age = 12.51±1.59 years) who regularly participate in the training process at a frequency of three times a week. All of our athletes had more than 4 years experiences with regular athletic training 3 times per week prior to this study. During a period of 8 weeks in the preparatory period, such exercises were applied which were performed unilaterally in EG1 and bilaterally in EG2. To determine the effectiveness of take-off training on change in the level of speed and speed-strength abilities, the following tests were performed: relative strength index (RSI), squat jump (SJ), countermovement jump (CMJ), standing long jump (SLJ), 20 m run from standing start. Results: We found out that in the posttest, the athletes of both groups achieved an improvement in the explosive strength of the lower extremities as well as in the acceleration speed. A significant improvement (p<0.05) was recorded in EG1 in SLJ and in EG2 in RSI. The effect size coefficients showed a large effect in RSI in EG2 and in SLJ in EG1. Conclusion: The results clearly did not confirm a higher effect of the unilateral program in comparison with the bilateral program, but indicated a higher efficiency, especially in the take-off explosiveness of athletes with a unilateral training program.