Acute Effects of Bilateral Versus Unilateral Isometric Conditioning Activity on Jump Performance in Volleyball Players (BI-UNI ICA)
13. července 2026 aktualizováno: 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.
Přehled studie
Postavení
Zápis na pozvánku
Detailní popis
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.
Typ studie
Intervenční
Zápis (Odhadovaný)
14
Fáze
- Nelze použít
Kontakty a umístění
Tato část poskytuje kontaktní údaje pro ty, kteří studii provádějí, a informace o tom, kde se tato studie provádí.
Studijní místa
-
-
Silesian Voivodeship
-
Katowice, Silesian Voivodeship, Polsko, 40-065
- Academy of Physical Education in Katowice
-
-
Kritéria účasti
Výzkumníci hledají lidi, kteří odpovídají určitému popisu, kterému se říká kritéria způsobilosti. Některé příklady těchto kritérií jsou celkový zdravotní stav osoby nebo předchozí léčba.
Kritéria způsobilosti
Věk způsobilý ke studiu
- Dítě
- Dospělý
- Starší dospělý
Přijímá zdravé dobrovolníky
Ano
Popis
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.
Studijní plán
Tato část poskytuje podrobnosti o studijním plánu, včetně toho, jak je studie navržena a co studie měří.
Jak je studie koncipována?
Detaily designu
- Primární účel: Základní věda
- Přidělení: Randomizované
- Intervenční model: Crossover Assignment
- Maskování: Žádné (otevřený štítek)
Zbraně a zásahy
Skupina účastníků / Arm |
Intervence / Léčba |
|---|---|
|
Experimentální: 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.
|
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.
Ostatní jména:
|
|
Experimentální: 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.
|
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.
Ostatní jména:
|
|
Experimentální: 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.
|
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.
|
Co je měření studie?
Primární výstupní opatření
Měření výsledku |
Popis opatření |
Časové okno |
|---|---|---|
|
Changes in Bilateral Countermovement Jump Height
Časové okno: Baseline and 4, 8, and 12 minutes after each experimental condition
|
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.
|
Baseline and 4, 8, and 12 minutes after each experimental condition
|
|
Changes in Single-Leg Jump Height
Časové okno: Baseline and 4, 8, and 12 minutes after each experimental condition
|
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.
|
Baseline and 4, 8, and 12 minutes after each experimental condition
|
Sekundární výstupní opatření
Měření výsledku |
Popis opatření |
Časové okno |
|---|---|---|
|
Changes in Bilateral Countermovement Jump Modified Reactive Strength Index
Časové okno: Baseline and 4, 8, and 12 minutes after each experimental condition
|
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.
|
Baseline and 4, 8, and 12 minutes after each experimental condition
|
|
Changes in Inter-Limb Concentric Impulse Asymmetry During the Bilateral Countermovement Jump
Časové okno: Baseline and 4, 8, and 12 minutes after each experimental condition
|
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.
|
Baseline and 4, 8, and 12 minutes after each experimental condition
|
|
Changes in Inter-Limb Single-Leg Jump Height Asymmetry
Časové okno: Baseline and 4, 8, and 12 minutes after each experimental condition
|
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.
|
Baseline and 4, 8, and 12 minutes after each experimental condition
|
Spolupracovníci a vyšetřovatelé
Zde najdete lidi a organizace zapojené do této studie.
Publikace a užitečné odkazy
Osoba odpovědná za zadávání informací o studiu tyto publikace poskytuje dobrovolně. Mohou se týkat čehokoli, co souvisí se studiem.
Obecné publikace
- 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.
Termíny studijních záznamů
Tato data sledují průběh záznamů studie a předkládání souhrnných výsledků na ClinicalTrials.gov. Záznamy ze studií a hlášené výsledky jsou před zveřejněním na veřejné webové stránce přezkoumány Národní lékařskou knihovnou (NLM), aby se ujistily, že splňují specifické standardy kontroly kvality.
Hlavní termíny studia
Začátek studia (Odhadovaný)
23. července 2026
Primární dokončení (Odhadovaný)
3. srpna 2026
Dokončení studie (Odhadovaný)
3. srpna 2026
Termíny zápisu do studia
První předloženo
13. července 2026
První předloženo, které splnilo kritéria kontroly kvality
13. července 2026
První zveřejněno (Aktuální)
16. července 2026
Aktualizace studijních záznamů
Poslední zveřejněná aktualizace (Aktuální)
16. července 2026
Odeslaná poslední aktualizace, která splnila kritéria kontroly kvality
13. července 2026
Naposledy ověřeno
1. července 2026
Více informací
Termíny související s touto studií
Klíčová slova
Další identifikační čísla studie
- 2-X/2025/002
Plán pro data jednotlivých účastníků (IPD)
Plánujete sdílet data jednotlivých účastníků (IPD)?
ANO
Popis plánu 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.
Časový rámec sdílení 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.
Kritéria přístupu pro sdílení 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.
Typ podpůrných informací pro sdílení IPD
- PROTOKOL STUDY
- MÍZA
Informace o lécích a zařízeních, studijní dokumenty
Studuje lékový produkt regulovaný americkým FDA
Ne
Studuje produkt zařízení regulovaný americkým úřadem FDA
Ne
Tyto informace byly beze změn načteny přímo z webu clinicaltrials.gov. Máte-li jakékoli požadavky na změnu, odstranění nebo aktualizaci podrobností studie, kontaktujte prosím register@clinicaltrials.gov. Jakmile bude změna implementována na clinicaltrials.gov, bude automaticky aktualizována i na našem webu .