Acute Effects of Bilateral Versus Unilateral Isometric Conditioning Activity on Jump Performance in Volleyball Players (BI-UNI ICA)
13. juli 2026 opdateret af: 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.
Studieoversigt
Status
Tilmelding efter invitation
Detaljeret beskrivelse
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.
Undersøgelsestype
Interventionel
Tilmelding (Anslået)
14
Fase
- Ikke anvendelig
Kontakter og lokationer
Dette afsnit indeholder kontaktoplysninger for dem, der udfører undersøgelsen, og oplysninger om, hvor denne undersøgelse udføres.
Studiesteder
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Silesian Voivodeship
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Katowice, Silesian Voivodeship, Polen, 40-065
- Academy of Physical Education in Katowice
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Deltagelseskriterier
Forskere leder efter personer, der passer til en bestemt beskrivelse, kaldet berettigelseskriterier. Nogle eksempler på disse kriterier er en persons generelle helbredstilstand eller tidligere behandlinger.
Berettigelseskriterier
Aldre berettiget til at studere
- Barn
- Voksen
- Ældre voksen
Tager imod sunde frivillige
Ja
Beskrivelse
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.
Studieplan
Dette afsnit indeholder detaljer om studieplanen, herunder hvordan undersøgelsen er designet, og hvad undersøgelsen måler.
Hvordan er undersøgelsen tilrettelagt?
Design detaljer
- Primært formål: Grundvidenskab
- Tildeling: Randomiseret
- Interventionel model: Crossover opgave
- Maskning: Ingen (Åben etiket)
Våben og indgreb
Deltagergruppe / Arm |
Intervention / Behandling |
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Eksperimentel: 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.
Andre navne:
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Eksperimentel: 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.
Andre navne:
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Eksperimentel: 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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Hvad måler undersøgelsen?
Primære resultatmål
Resultatmål |
Foranstaltningsbeskrivelse |
Tidsramme |
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Changes in Bilateral Countermovement Jump Height
Tidsramme: 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
Tidsramme: 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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Sekundære resultatmål
Resultatmål |
Foranstaltningsbeskrivelse |
Tidsramme |
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Changes in Bilateral Countermovement Jump Modified Reactive Strength Index
Tidsramme: 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
Tidsramme: 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
Tidsramme: 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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Samarbejdspartnere og efterforskere
Det er her, du vil finde personer og organisationer, der er involveret i denne undersøgelse.
Publikationer og nyttige links
Den person, der er ansvarlig for at indtaste oplysninger om undersøgelsen, leverer frivilligt disse publikationer. Disse kan handle om alt relateret til undersøgelsen.
Generelle publikationer
- 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.
Datoer for undersøgelser
Disse datoer sporer fremskridtene for indsendelser af undersøgelsesrekord og resumeresultater til ClinicalTrials.gov. Studieregistreringer og rapporterede resultater gennemgås af National Library of Medicine (NLM) for at sikre, at de opfylder specifikke kvalitetskontrolstandarder, før de offentliggøres på den offentlige hjemmeside.
Studer store datoer
Studiestart (Anslået)
23. juli 2026
Primær færdiggørelse (Anslået)
3. august 2026
Studieafslutning (Anslået)
3. august 2026
Datoer for studieregistrering
Først indsendt
13. juli 2026
Først indsendt, der opfyldte QC-kriterier
13. juli 2026
Først opslået (Faktiske)
16. juli 2026
Opdateringer af undersøgelsesjournaler
Sidste opdatering sendt (Faktiske)
16. juli 2026
Sidste opdatering indsendt, der opfyldte kvalitetskontrolkriterier
13. juli 2026
Sidst verificeret
1. juli 2026
Mere information
Begreber relateret til denne undersøgelse
Nøgleord
Andre undersøgelses-id-numre
- 2-X/2025/002
Plan for individuelle deltagerdata (IPD)
Planlægger du at dele individuelle deltagerdata (IPD)?
JA
IPD-planbeskrivelse
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.
IPD-delingstidsramme
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.
IPD-delingsadgangskriterier
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.
IPD-deling Understøttende informationstype
- STUDY_PROTOCOL
- SAP
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