Acute Effects of Bilateral Versus Unilateral Isometric Conditioning Activity on Jump Performance in Volleyball Players (BI-UNI ICA)
13 luglio 2026 aggiornato da: The Jerzy Kukuczka Academy of Physical Education in Katowice
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
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.
Panoramica dello studio
Stato
Iscrizione su invito
Condizioni
Descrizione dettagliata
This study is a randomized, counterbalanced crossover trial designed to examine the acute effects of unilateral and bilateral isometric conditioning activity on jump performance in highly trained male volleyball players. Fourteen participants will complete three experimental conditions on separate occasions in randomized order: bilateral isometric conditioning activity (BI), unilateral isometric conditioning activity (UNI), and a control condition (CTRL). Because each participant will complete all three conditions, every athlete will serve as his own control.
Each experimental session will begin with a standardized warm-up consisting of 5 minutes of cycling followed by bodyweight squats, walking lunges, thoracic spine rotations, and submaximal countermovement jumps. Baseline jump performance will then be assessed using two bilateral countermovement jumps and two single-leg jumps performed separately with each lower limb. The single-leg jump will involve take-off from one limb and landing on both limbs.
In the BI condition, participants will perform three sets of three maximal 3-second bilateral isometric squat contractions against an immovable resistance, with 3-minute recovery intervals between sets. In the UNI condition, participants will perform three sets of three maximal 3-second unilateral isometric squat contractions with each lower limb. The limbs will be alternated to reduce systematic differences in recovery time between sides. In the CTRL condition, participants will complete 9 minutes of low-intensity treadmill walking at 6 km/h.
Following each experimental condition, bilateral countermovement jump and single-leg jump performance will be reassessed at 4, 8, and 12 minutes. All jumps will be performed on force platforms. The primary outcome will be bilateral countermovement jump height. Secondary outcomes will include single-leg jump height and selected force-time variables derived from the bilateral and unilateral jump tests.
The primary objective of the study is to compare the acute effects of unilateral and bilateral isometric conditioning activity on bilateral countermovement jump performance. A secondary objective is to determine whether the type of conditioning activity produces task-specific effects on unilateral jump performance and whether the time course of post-activation performance enhancement differs between the BI and UNI conditions.
Tipo di studio
Interventistico
Iscrizione (Stimato)
14
Fase
- Non applicabile
Contatti e Sedi
Questa sezione fornisce i recapiti di coloro che conducono lo studio e informazioni su dove viene condotto lo studio.
Luoghi di studio
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Silesian Voivodeship
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Katowice, Silesian Voivodeship, Polonia, 40-065
- Academy of Physical Education in Katowice
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Criteri di partecipazione
I ricercatori cercano persone che corrispondano a una certa descrizione, chiamata criteri di ammissibilità. Alcuni esempi di questi criteri sono le condizioni generali di salute di una persona o trattamenti precedenti.
Criteri di ammissibilità
Età idonea allo studio
- Bambino
- Adulto
- Adulto più anziano
Accetta volontari sani
Sì
Descrizione
Inclusion Criteria:
- minimum of 7 years of systematic volleyball training,
- at least 3 resistance training sessions per week during the preceding 5 years,
- no musculoskeletal injury requiring training cessation longer than 4 weeks within 6 months prior to enrollment,
- absence of tattoos over the rectus femoris muscle that could interfere with thermographic assessment.
Exclusion Criteria:
- less than 7 years of systematic volleyball training,
- less than 3 resistance training sessions per week during the previous 5 years,
- any musculoskeletal injury within the 6 months prior to enrollment that required cessation of training for longer than 4 weeks,
- current musculoskeletal pain or injury that could affect jumping performance or participation in maximal isometric exercise,
- tattoos, scars, or skin conditions over the rectus femoris muscle that could interfere with thermographic measurements,
- use of medications or substances that may affect neuromuscular performance or muscle function,
- failure to comply with study procedures or testing requirements.
Piano di studio
Questa sezione fornisce i dettagli del piano di studio, compreso il modo in cui lo studio è progettato e ciò che lo studio sta misurando.
Come è strutturato lo studio?
Dettagli di progettazione
- Scopo principale: Scienza basilare
- Assegnazione: Randomizzato
- Modello interventistico: Assegnazione incrociata
- Mascheramento: Nessuno (etichetta aperta)
Armi e interventi
Gruppo di partecipanti / Arm |
Intervento / Trattamento |
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Sperimentale: Bilateral Isometric Conditioning Activity
Participants will perform a bilateral isometric conditioning activity consisting of three sets of three maximal 3-second isometric squat contractions against an immovable resistance.
Each set will be separated by 3 minutes of recovery.
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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.
Altri nomi:
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Sperimentale: Unilateral Isometric Conditioning Activity
Participants will perform a unilateral isometric conditioning activity consisting of three sets of three maximal 3-second isometric squat contractions with each lower limb against an immovable resistance.
The lower limbs will be alternated, and each set will be separated by 3 minutes of recovery.
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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.
Altri nomi:
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Sperimentale: Control Condition
Participants will complete 9 minutes of low-intensity treadmill walking at a speed of 6 km/h.
This condition will serve as the control condition for comparison with the bilateral and unilateral isometric conditioning activities.
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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.
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Cosa sta misurando lo studio?
Misure di risultato primarie
Misura del risultato |
Misura Descrizione |
Lasso di tempo |
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Changes in Bilateral Countermovement Jump Height
Lasso di tempo: Baseline and 4, 8, and 12 minutes after each experimental condition
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Bilateral countermovement jump height will be assessed using dual force platforms operating at a sampling frequency of 1000 Hz.
Jump height will be calculated from center-of-mass take-off velocity using the impulse-momentum method and expressed in centimeters.
Participants will perform two valid trials at each time point, and the mean value will be used for analysis.
Changes from the condition-specific baseline will be compared between the bilateral isometric, unilateral isometric, and control conditions.
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Baseline and 4, 8, and 12 minutes after each experimental condition
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Changes in Single-Leg Jump Height
Lasso di tempo: Baseline and 4, 8, and 12 minutes after each experimental condition
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Single-leg jump height will be assessed separately for the right and left lower limbs using force platforms.
Each jump will be performed with take-off from one limb and landing on both limbs.
Jump height will be calculated from center-of-mass take-off velocity using the impulse-momentum method and expressed in centimeters.
Two valid trials will be performed with each limb at each time point, and the mean value for each limb will be used for analysis.
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Baseline and 4, 8, and 12 minutes after each experimental condition
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Misure di risultato secondarie
Misura del risultato |
Misura Descrizione |
Lasso di tempo |
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Changes in Bilateral Countermovement Jump Modified Reactive Strength Index
Lasso di tempo: Baseline and 4, 8, and 12 minutes after each experimental condition
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The modified reactive strength index during the bilateral countermovement jump will be calculated as jump height in meters divided by time to take-off in seconds and expressed in meters per second.
Participants will perform two valid trials at each time point, and the mean value will be used for analysis.
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Baseline and 4, 8, and 12 minutes after each experimental condition
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Changes in Inter-Limb Concentric Impulse Asymmetry During the Bilateral Countermovement Jump
Lasso di tempo: Baseline and 4, 8, and 12 minutes after each experimental condition
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Concentric impulse will be calculated separately for the right and left lower limbs from force-time data recorded using dual force platforms.
Inter-limb asymmetry will be expressed as a percentage and calculated using the following formula: absolute difference between limbs divided by the higher limb value, multiplied by 100.
A value of 0% represents perfect symmetry, while higher values indicate greater inter-limb asymmetry.
The mean of two valid trials will be used for analysis.
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Baseline and 4, 8, and 12 minutes after each experimental condition
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Changes in Inter-Limb Single-Leg Jump Height Asymmetry
Lasso di tempo: Baseline and 4, 8, and 12 minutes after each experimental condition
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Inter-limb asymmetry in single-leg jump height will be calculated from the mean jump height obtained separately for the right and left lower limbs.
Asymmetry will be expressed as a percentage and calculated as the absolute difference between limbs divided by the higher limb value, multiplied by 100.
A value of 0% represents perfect symmetry, while higher values indicate greater inter-limb asymmetry.
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Baseline and 4, 8, and 12 minutes after each experimental condition
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Collaboratori e investigatori
Qui è dove troverai le persone e le organizzazioni coinvolte in questo studio.
Pubblicazioni e link utili
La persona responsabile dell'inserimento delle informazioni sullo studio fornisce volontariamente queste pubblicazioni. Questi possono riguardare qualsiasi cosa relativa allo studio.
Pubblicazioni generali
- Helbin J, Gawel D, Terbalyan A, Wilk M, Krzysztofik M, Lum D, Jarosz J. Acute Effects of Isometric Contraction Distribution on Jump Performance in Volleyball Players. J Funct Morphol Kinesiol. 2025 Sep 9;10(3):343. doi: 10.3390/jfmk10030343.
- Jarosz J, Szwarc A. Isometric Conditioning Activity and Jump Performance: Impact of Training Status in Male Participants. J Clin Med. 2025 Sep 3;14(17):6214. doi: 10.3390/jcm14176214.
- Krzysztofik M, Wilk M, Pisz A, Kolinger D, Tsoukos A, Aschenbrenner P, Stastny P, Bogdanis GC. Effects of Unilateral Conditioning Activity on Acute Performance Enhancement: A Systematic Review. J Sports Sci Med. 2022 Dec 1;21(4):625-639. doi: 10.52082/jssm.2022.625. eCollection 2022 Dec.
- Lum D, Barbosa TM. Brief Review: Effects of Isometric Strength Training on Strength and Dynamic Performance. Int J Sports Med. 2019 May;40(6):363-375. doi: 10.1055/a-0863-4539. Epub 2019 Apr 3.
- Jarosz J, Drozd M, Gawel D, Wilk M, Helbin J, Krzysztofik M. Acute effects of isometric conditioning activity with different distribution contraction on countermovement jump performance in resistance trained participants. Sci Rep. 2025 May 15;15(1):16960. doi: 10.1038/s41598-025-02126-4.
Studiare le date dei record
Queste date tengono traccia dell'avanzamento della registrazione dello studio e dell'invio dei risultati di sintesi a ClinicalTrials.gov. I record degli studi e i risultati riportati vengono esaminati dalla National Library of Medicine (NLM) per assicurarsi che soddisfino specifici standard di controllo della qualità prima di essere pubblicati sul sito Web pubblico.
Studia le date principali
Inizio studio (Stimato)
23 luglio 2026
Completamento primario (Stimato)
3 agosto 2026
Completamento dello studio (Stimato)
3 agosto 2026
Date di iscrizione allo studio
Primo inviato
13 luglio 2026
Primo inviato che soddisfa i criteri di controllo qualità
13 luglio 2026
Primo Inserito (Effettivo)
16 luglio 2026
Aggiornamenti dei record di studio
Ultimo aggiornamento pubblicato (Effettivo)
16 luglio 2026
Ultimo aggiornamento inviato che soddisfa i criteri QC
13 luglio 2026
Ultimo verificato
1 luglio 2026
Maggiori informazioni
Termini relativi a questo studio
Parole chiave
Altri numeri di identificazione dello studio
- 2-X/2025/002
Piano per i dati dei singoli partecipanti (IPD)
Hai intenzione di condividere i dati dei singoli partecipanti (IPD)?
SÌ
Descrizione del piano IPD
De-identified individual participant data will be shared upon reasonable request after publication of the study results.
Requests should be directed to the corresponding author.
Periodo di condivisione IPD
De-identified individual participant data and supporting documents will be available beginning 3 months after publication of the primary study results and will remain available for 5 years.
Criteri di accesso alla condivisione IPD
De-identified individual participant data and supporting documents will be made available to qualified researchers who submit a methodologically sound research proposal.
Requests should be directed to the corresponding author and will be reviewed by the study investigators.
Access will be granted for analyses consistent with the approved proposal and may require a data-use agreement.
Tipo di informazioni di supporto alla condivisione IPD
- STUDIO_PROTOCOLLO
- LINFA
Informazioni su farmaci e dispositivi, documenti di studio
Studia un prodotto farmaceutico regolamentato dalla FDA degli Stati Uniti
No
Studia un dispositivo regolamentato dalla FDA degli Stati Uniti
No
Queste informazioni sono state recuperate direttamente dal sito web clinicaltrials.gov senza alcuna modifica. In caso di richieste di modifica, rimozione o aggiornamento dei dettagli dello studio, contattare register@clinicaltrials.gov. Non appena verrà implementata una modifica su clinicaltrials.gov, questa verrà aggiornata automaticamente anche sul nostro sito web .