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Isometric vs. Dynamic Squat Pre-Loading: Acute PAPE Responses (IPP vs DPP)

6. Juli 2026 aktualisiert von: Neslihan AKÇAY, Karabuk University

Acute Post-Activation Performance Responses to Isometric and Dynamic Squat Pre-Loading Protocols: A Randomized Crossover Trial

This randomized crossover study compared the acute post-activation performance responses to isometric and dynamic squat-based preconditioning protocols performed with and without electromyostimulation (EMS). Participants completed five randomized experimental conditions: maximal voluntary isometric contraction (MVIC), dynamic contraction (DC), MVIC+EMS, DC+EMS, and EMS only (O-EMS). Baseline and post-intervention assessments included countermovement jump (CMJ), countermovement jump with arm swing (CMJWH), zig-zag agility, and shooting speed, with post-tests conducted after a 4-minute recovery period. Perceptual responses, including ratings of perceived exertion (RPE), perceived discomfort (RPD), and fatigue (VAS), were recorded immediately after each protocol. All sessions were conducted between 14:00 and 16:00 under standardized conditions, with protocol order randomized and participants instructed to avoid strenuous exercise and food intake before testing.

Studienübersicht

Status

Noch keine Rekrutierung

Bedingungen

Intervention / Behandlung

Detaillierte Beschreibung

This study aimed to compare the acute post-activation performance responses to isometric and dynamic squat-based preconditioning protocols, with and without EMS. All testing sessions were conducted between 14:00 and 16:00 to minimize the potential effects of circadian rhythms and fatigue on performance. The study was conducted using a randomized, crossover design. On the remaining five experimental days, the order of the protocols was randomized for each participant using a computer-generated randomization sequence (randomizer.org) to reduce order effects. During the first session, participants' anthropometric measurements were recorded, their one-repetition maximum (1RM) back squat loads were determined, and they were familiarized with the equipment and testing procedures. Participants completed five separate experimental sessions consisting of the following conditions: [A] Isometric Contraction + EMS (MVIC-EMS), [B] Dynamic Contraction + EMS (DC-EMS), [C] Dynamic Contraction (DC), [D] Isometric Contraction (MVIC), and [E] Only EMS (O-EMS). Before each experimental protocol, baseline measurements were obtained using countermovement jump (CMJ), CMJ with hands (CMJWH), zig-zag agility test, and shooting speed assessments. After each protocol, all tests were repeated after a 4-minute rest period (Chen et al., 2023). Under all conditions, the electrodes were placed identically by the same experienced researcher. Subsequently, players' shooting speeds were measured using a radar gun, with two trials performed and the highest value recorded. Immediately after each experimental protocol, ratings of perceived exertion (RPE), perceived discomfort (RPD), and perceived fatigue level were assessed using a visual analog scale (VAS) and recorded. Participants were instructed to refrain from food intake for 1.5 hours before testing, to avoid resistance training throughout the study period, and were verbally encouraged during all testing sessions.

Studientyp

Interventionell

Einschreibung (Geschätzt)

22

Phase

  • Unzutreffend

Kontakte und Standorte

Dieser Abschnitt enthält die Kontaktdaten derjenigen, die die Studie durchführen, und Informationen darüber, wo diese Studie durchgeführt wird.

Studienkontakt

Studieren Sie die Kontaktsicherung

  • Name: Neslihan Akçay, Doctorate

Studienorte

    • Turkey
      • Karabük, Turkey, Türkei (türkiye), 78200
        • Karabuk University
        • Kontakt:
        • Hauptermittler:
          • Neslihan Akçay, Doctorate
        • Unterermittler:
          • Cem Sofuoğlu
        • Unterermittler:
          • Wolfgang Kemmler, Prof.Dr.
        • Unterermittler:
          • Andre Filipovic, Prof.Dr.
        • Unterermittler:
          • Metehan Yana, Doctorate
        • Unterermittler:
          • Erşan Arslan, Prof.Dr.

Teilnahmekriterien

Forscher suchen nach Personen, die einer bestimmten Beschreibung entsprechen, die als Auswahlkriterien bezeichnet werden. Einige Beispiele für diese Kriterien sind der allgemeine Gesundheitszustand einer Person oder frühere Behandlungen.

Zulassungskriterien

Studienberechtigtes Alter

  • Erwachsene

Akzeptiert gesunde Freiwillige

Ja

Beschreibung

Inclusion Criteria:

  • Being healthy
  • Male volleyball athletes
  • Willing to maintain the intervention for all sessions

Exclusion Criteria:

  • Being under 18 years old
  • Having a chronic disease
  • Contraindications for exercise

Studienplan

Dieser Abschnitt enthält Einzelheiten zum Studienplan, einschließlich des Studiendesigns und der Messung der Studieninhalte.

Wie ist die Studie aufgebaut?

Designdetails

  • Hauptzweck: Behandlung
  • Zuteilung: Zufällig
  • Interventionsmodell: Crossover-Aufgabe
  • Maskierung: Single

Waffen und Interventionen

Teilnehmergruppe / Arm
Intervention / Behandlung
Experimental: Condition 1
Dynamic contraction
Participants performed a dynamic back squat conditioning protocol on a Smith machine consisting of five sets of one repetition at 90% of one-repetition maximum (1RM), with 1 min of passive recovery between sets. Each repetition included a controlled descent to approximately 90° of knee flexion, an explosive concentric phase, a 2-s isometric hold at full knee extension, and a slow, controlled eccentric phase (Pincivero et al.). All repetitions were supervised to ensure proper technique. The protocol was selected based on previous evidence supporting high-intensity resistance exercise as an effective conditioning activity for inducing PAPE responses (Dobbs et al.).
Experimental: Condition 2
isometric contraction
The isometric contraction protocol was conducted as described by Koźlenia and Domaradzki (2023) and Lim and Kong (2013). Participants assumed a squat position in a squat rack with the barbell fixed in place and the knee joint positioned at approximately 90° of flexion (Profitness 1030, Türkiye). The barbell was secured to the rack using safety pins, and participants were instructed to exert maximal force against the immovable bar to produce a MVIC. Each contraction lasted 3 seconds, and a total of 3 repetitions were performed with 2 min of rest between repetitions (Koźlenia & Domaradzki, 2023; Lim & Kong, 2013).
Experimental: Condition 3
Dynamic + EMS contraction
Participants performed a dynamic back squat conditioning protocol on a Smith machine consisting of five sets of one repetition at 90% of one-repetition maximum (1RM), with 1 min of passive recovery between sets. In the DC-EMS condition, electromyostimulation (EMS) was applied simultaneously throughout the conditioning protocol. Each repetition included a controlled descent to approximately 90° of knee flexion, an explosive concentric phase, a 2-s isometric hold at full knee extension, and a slow, controlled eccentric phase (Pincivero et al.). All repetitions were supervised to ensure proper technique. The protocol was selected based on previous evidence supporting high-intensity resistance exercise as an effective conditioning activity for inducing PAPE responses (Dobbs et al.).
Experimental: Condition 4
Isometric + EMS Contraction
The isometric contraction protocol was conducted as described by Koźlenia and Domaradzki (2023) and Lim and Kong (2013). Participants assumed a squat position in a squat rack with the barbell fixed in place and the knee joint positioned at approximately 90° of flexion (Profitness 1030, Türkiye). The barbell was secured to the rack using safety pins, and participants were instructed to exert maximal force against the immovable bar to produce an MVIC. Each contraction lasted 3 seconds, and a total of three repetitions were performed with 2 min of rest between repetitions (Koźlenia & Domaradzki, 2023; Lim & Kong, 2013). In the MVIC-EMS condition, electromyostimulation (EMS) was applied simultaneously during each maximal voluntary isometric contraction.
Experimental: Condition 5
EMS contraction
EMS was delivered bilaterally to the quadriceps using a portable stimulator (Compex Rehab 400, Compex Medical SA, Switzerland) with a biphasic symmetrical rectangular waveform (75 Hz, 450 μs). Four self-adhesive electrodes were placed over the vastus medialis and vastus lateralis muscles of both legs. Participants remained seated for 10 min with the knees flexed at approximately 90° and the hips flexed at approximately 110°, while receiving EMS without performing any voluntary contractions. Stimulation intensity was gradually increased to the highest level tolerated by each participant and maintained throughout the intervention (Paillard et al., 2008; Sofuoğlu et al., 2025).

Was misst die Studie?

Primäre Ergebnismessungen

Ergebnis Maßnahme
Maßnahmenbeschreibung
Zeitfenster
Countermovement Jump (CMJ) Height
Zeitfenster: aseline and 4 minutes after each experimental condition
Change in countermovement jump (CMJ) height (cm) from baseline to 4 minutes after each conditioning protocol, measured using a jump assessment system.
aseline and 4 minutes after each experimental condition
Countermovement Jump with Arm Swing (CMJWH) Height
Zeitfenster: Baseline and 4 minutes after each experimental condition
Change in countermovement jump with arm swing (CMJWH) height (cm) from baseline to 4 minutes after each conditioning protocol.
Baseline and 4 minutes after each experimental condition
Zig-Zag Agility Performance
Zeitfenster: Baseline and 4 minutes after each experimental condition
Change in zig-zag agility performance time (s) from baseline to 4 minutes after each conditioning protocol.
Baseline and 4 minutes after each experimental condition
Shooting Speed
Zeitfenster: Baseline and 4 minutes after each experimental condition
Change in maximal shooting speed (km/h) from baseline to 4 minutes after each conditioning protocol, measured using a radar gun.
Baseline and 4 minutes after each experimental condition

Sekundäre Ergebnismessungen

Ergebnis Maßnahme
Maßnahmenbeschreibung
Zeitfenster
Rating of Perceived Exertion (RPE)
Zeitfenster: Immediately after each experimental condition
Rating of perceived exertion assessed immediately after each conditioning protocol using the Borg CR-10 scale.
Immediately after each experimental condition
Rating of Perceived Discomfort (RPD)
Zeitfenster: Immediately after each experimental condition
Rating of perceived discomfort assessed immediately after each conditioning protocol using the Borg CR-10 scale.
Immediately after each experimental condition
Perceived Fatigue
Zeitfenster: Immediately after each experimental condition
Perceived fatigue assessed immediately after each conditioning protocol using a visual analog scale (VAS).
Immediately after each experimental condition

Mitarbeiter und Ermittler

Hier finden Sie Personen und Organisationen, die an dieser Studie beteiligt sind.

Sponsor

Ermittler

  • Studienstuhl: Neslihan Akçay, Doctorate, Karabuk University

Publikationen und hilfreiche Links

Die Bereitstellung dieser Publikationen erfolgt freiwillig durch die für die Eingabe von Informationen über die Studie verantwortliche Person. Diese können sich auf alles beziehen, was mit dem Studium zu tun hat.

Studienaufzeichnungsdaten

Diese Daten verfolgen den Fortschritt der Übermittlung von Studienaufzeichnungen und zusammenfassenden Ergebnissen an ClinicalTrials.gov. Studienaufzeichnungen und gemeldete Ergebnisse werden von der National Library of Medicine (NLM) überprüft, um sicherzustellen, dass sie bestimmten Qualitätskontrollstandards entsprechen, bevor sie auf der öffentlichen Website veröffentlicht werden.

Haupttermine studieren

Studienbeginn (Geschätzt)

1. August 2026

Primärer Abschluss (Geschätzt)

30. August 2026

Studienabschluss (Geschätzt)

5. September 2026

Studienanmeldedaten

Zuerst eingereicht

6. Juli 2026

Zuerst eingereicht, das die QC-Kriterien erfüllt hat

6. Juli 2026

Zuerst gepostet (Tatsächlich)

10. Juli 2026

Studienaufzeichnungsaktualisierungen

Letztes Update gepostet (Tatsächlich)

10. Juli 2026

Letztes eingereichtes Update, das die QC-Kriterien erfüllt

6. Juli 2026

Zuletzt verifiziert

1. Juli 2026

Mehr Informationen

Begriffe im Zusammenhang mit dieser Studie

Andere Studien-ID-Nummern

  • UKarabuk-6

Plan für individuelle Teilnehmerdaten (IPD)

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UNENTSCHIEDEN

Arzneimittel- und Geräteinformationen, Studienunterlagen

Studiert ein von der US-amerikanischen FDA reguliertes Arzneimittelprodukt

Nein

Studiert ein von der US-amerikanischen FDA reguliertes Geräteprodukt

Nein

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