Effects of 6-Week Plyometric Training on Vertical Jump Performance and Muscle Activation of Lower Extremity Muscles

Author: Kerim SOZBIR*(1)

(1)Kerim SOZBIR is an Assistant Professor and lectures Human Anatomy and Physiology, Speed Training, and Track and Field in the Department of Coaching Education at the University of Abant Izzet Baysal in TURKEY. He is also Head Coach of University Table Tennis, and Track and Field Teams.

*Corresponding Author:
Kerim SOZBIR, Ph.D
Department of Coaching Education, School of Physical Education and Sports,
University of Abant Izzet Baysal, Golkoy Kampusu, 14030, Bolu/TURKEY
Office Phone: +903742541000 (ext. 2027)
Fax: +90 374 2534636
Email: sozbir_k@ibu.edu.tr

ABSTRACT
The purpose of this study was to determine the effects of 6-week plyometric training on vertical jump performance and electromyography (EMG) activities of vastus lateralis (VL), vastus medialis (VM), and gastrocnemius (GAS) muscles during countermovement jump (CMJ). Twenty-four highly physically active physical education students were randomly assigned either to a plyometric (PLY) group or a control group. The experimental group performed plyometric exercises 2 times a week for 6 weeks, whereas the control group participated only in their lectures. The results revealed that there were no significant changes in either vertical jump height or EMG activities of selected muscles for the control group (p greater than 0.05). However, after 6 weeks of plyometric training, significant improvements (p less than 0.05) were observed in EMG activities of VL (13.25%), VM (9.60%), and GAS (13.93%) muscles, and no significant increase (p greater than 0.05) was found in CMJ (2.77%) in the PLY group. In conclusion, the findings of the this study suggest that 6 weeks of PLY training, in addition to the regular academic program, induced significant improvements in EMG activities of lower extremity muscles but no significant increases in vertical jump height. Accordingly, PLY exercises are recommended as part of a regular academic program in order to increase important components of athletic performance for physical education students.

KEYWORDS: Stretch-shortening cycle, electromyography, root mean square, countermovement jump, knee extensor muscles.
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