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Acute Effects of Bilateral Versus Unilateral Isometric Conditioning Activity on Jump Performance in Volleyball Players
Sponsor: The Jerzy Kukuczka Academy of Physical Education in Katowice
Summary
This randomized crossover trial investigates the acute effects of bilateral and unilateral isometric conditioning activity on bilateral and unilateral jump performance in highly trained male volleyball players. Fourteen athletes will complete three experimental conditions in randomized order: bilateral isometric squat conditioning activity (BI), unilateral isometric squat conditioning activity (UNI), and a control condition consisting of low-intensity treadmill walking (CTRL). In both isometric conditions, participants will perform three sets of three maximal 3-second contractions, with 3-minute recovery intervals between sets. Jump performance will be assessed before each experimental condition and at 4, 8, and 12 minutes afterward using bilateral countermovement jumps and single-leg jumps performed separately with each lower limb. The primary aim of the study is to determine whether the mode of isometric conditioning activity, unilateral versus bilateral, influences the magnitude and time course of acute changes in jump performance. An additional objective is to assess whether the effects of the conditioning activity differ between bilateral and unilateral jumping tasks.
Official title: Acute Effects of Bilateral Versus Unilateral Isometric Conditioning Activity on Bilateral and Unilateral Jump Performance in Highly Trained Male Volleyball Players: A Randomized Crossover Trial
Key Details
Gender
MALE
Age Range
Any - Any
Study Type
INTERVENTIONAL
Enrollment
14
Start Date
2026-07-23
Completion Date
2026-08-03
Last Updated
2026-07-16
Healthy Volunteers
Yes
Interventions
Bilateral Isometric Conditioning Activity
Three sets of three maximal 3-second bilateral isometric squat contractions performed against an immovable resistance, with 3-minute recovery intervals between sets. Participants will be instructed to push as hard and as fast as possible during each contraction.
Unilateral Isometric Conditioning Activity
Three sets of three maximal 3-second unilateral isometric squat contractions performed with each lower limb against an immovable resistance. The lower limbs will be alternated, and 3-minute recovery intervals will be provided between sets. Participants will be instructed to push as hard and as fast as possible during each contraction.
Low-Intensity Treadmill Walking
All participants will complete all three experimental conditions in a randomized and counterbalanced order, with a standardized recovery interval between sessions. Each participant will therefore serve as his own control.
Locations (1)
Academy of Physical Education in Katowice
Katowice, Silesian Voivodeship, Poland