Acute Effects of Functional Inspiratory Muscle Training in Elite Male Volleyball Players

NCT07763002 | Recruiting

• 1 other identifier: Gazi2729
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

This randomized controlled trial evaluates the acute effects of a single session of functional inspiratory muscle training on muscle oxygenation, exercise capacity, dynamic balance, and agility in elite male volleyball players aged 18 to 25 years. Thirty participants will be randomly assigned in a 1:1 ratio to an intervention group or a no-intervention control group. The intervention group will perform 60 resisted breaths at 50% of maximal inspiratory pressure using a POWERbreathe device during a sport-specific fixed-ball throwing drill. Both groups will complete assessments before and immediately after the intervention period on the same day. Quadriceps muscle oxygen saturation and total hemoglobin will be measured using a Moxy near-infrared spectroscopy monitor during the Incremental Shuttle Walk Test. Exercise capacity, dynamic balance, and agility will be assessed using the Incremental Shuttle Walk Test, Star Excursion Balance Test, and T-Test, respectively.

Conditions

Athletic Performance

Keywords

functional inspiratory muscle training; inspiratory muscle training; elite volleyball players; muscle oxygenation; near-infrared spectroscopy; Moxy Monitor; Incremental Shuttle Walk Test; dynamic balance; agility

Outcome Measures

Primary Outcomes (2)

• Change in Quadriceps Total Hemoglobin During the Incremental Shuttle Walk Test

  Total hemoglobin (THb, g/dL) will be recorded continuously using a Moxy near-infrared spectroscopy monitor positioned over the midpoint of the right quadriceps femoris. Mean THb will be summarized separately for the pre-exercise rest, exercise, and recovery phases of the Incremental Shuttle Walk Test. For each phase, change will be calculated as the post-intervention value minus the pre-intervention value. The primary comparison will be the difference in pre-to-post change between the intervention and control groups.

  Baseline and immediately after the single-session intervention or control period, within the same day

• Change in Quadriceps Muscle Oxygen Saturation During the Incremental Shuttle Walk Test

  Muscle oxygen saturation (SmO2, %) will be recorded continuously using a Moxy near-infrared spectroscopy monitor positioned over the midpoint of the right quadriceps femoris. Mean SmO2 will be summarized separately for the pre-exercise rest, exercise, and recovery phases of the Incremental Shuttle Walk Test. For each phase, change will be calculated as the post-intervention value minus the pre-intervention value. The primary comparison will be the difference in pre-to-post change between the intervention and control groups.

  Baseline and immediately after the single-session intervention or control period, within the same day

Secondary Outcomes (3)

• Change in Incremental Shuttle Walk Test Distance

  Baseline and immediately after the single-session intervention or control period, within the same day

• Change in Normalized Star Excursion Balance Test Reach Distance

  Baseline and immediately after the single-session intervention or control period, within the same day

• Change in T-Test Agility Completion Time

  Baseline and immediately after the single-session intervention or control period, within the same day

Study Arms (2)

Functional Inspiratory Muscle Training

EXPERIMENTAL

Fifteen participants are planned for this arm. After warm-up, participants perform a sport-specific fixed-ball throwing drill while completing a single session of functional inspiratory muscle training using a POWERbreathe device. The resistance is set at 50% of the individual's maximal inspiratory pressure. Training consists of two sets of 30 resisted breaths, for a total of 60 breaths over approximately 10 to 12 minutes.

Device: Functional Inspiratory Muscle Training With POWERbreathe

No-Intervention Control

NO INTERVENTION

Fifteen participants are planned for this arm. Participants receive no inspiratory muscle training and complete the same pre-intervention and post-intervention outcome assessments as the intervention group on the same day.

Interventions

Functional Inspiratory Muscle Training With POWERbreathe DEVICE

A POWERbreathe pressure-threshold inspiratory muscle training device is used during a sport-specific fixed-ball throwing drill after warm-up. Before training, maximal inspiratory pressure is measured using a mouth pressure meter. The device resistance is individualized at 50% of maximal inspiratory pressure. Participants complete two sets of 30 resisted inspirations, totaling 60 breaths, over approximately 10 to 12 minutes. Expiration is unrestricted. The intervention is delivered once.

Functional Inspiratory Muscle Training

Eligibility Criteria

• Age: 18 Years - 25 Years
• Sex: male
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Male, aged 18 to 25 years
• Regular participation in volleyball training
• University student actively playing on an elite-level volleyball team
• Regular training during the previous 3 months
• Willing and able to provide written informed consent

You may not qualify if:

• Current smoking or regular alcohol use
• Regular use of medication or vitamin supplements
• History of upper respiratory tract infection or COVID-19 within the previous 3 months
• Lower-extremity or shoulder surgery within the previous 6 months
• An acute respiratory or musculoskeletal condition that prevents safe completion of the protocol
• Inability to complete the assessment or training procedures

Sponsors & Collaborators

• Gazi University: lead

Study Sites (1)

Gazi University Faculty of Health Sciences Department of Cardiopulmonary Physiotherapy and Rehabilitation, Ankara, Çankaya 06490

Ankara, Ankara, 06560, Turkey (Türkiye)

RECRUITING

Related Publications (8)

• Vivas-Mateos G, Livingstone IAT, Hamilton R, Cheema A, Giardini ME. Too Many Shades of Grey: Photometrically and Spectrally Mismatched Targets and Backgrounds in Printed Acuity Tests for Infants and Young Children. Transl Vis Sci Technol. 2020 Nov 6;9(12):12. doi: 10.1167/tvst.9.12.12. eCollection 2020 Nov.

  PMID: 33240565 BACKGROUND

• Gribble PA, Hertel J, Plisky P. Using the Star Excursion Balance Test to assess dynamic postural-control deficits and outcomes in lower extremity injury: a literature and systematic review. J Athl Train. 2012 May-Jun;47(3):339-57. doi: 10.4085/1062-6050-47.3.08.

  PMID: 22892416 BACKGROUND

• Probst VS, Hernandes NA, Teixeira DC, Felcar JM, Mesquita RB, Goncalves CG, Hayashi D, Singh S, Pitta F. Reference values for the incremental shuttle walking test. Respir Med. 2012 Feb;106(2):243-8. doi: 10.1016/j.rmed.2011.07.023. Epub 2011 Aug 23.

  PMID: 21865021 BACKGROUND

• Singh SJ, Morgan MD, Scott S, Walters D, Hardman AE. Development of a shuttle walking test of disability in patients with chronic airways obstruction. Thorax. 1992 Dec;47(12):1019-24. doi: 10.1136/thx.47.12.1019.

  PMID: 1494764 BACKGROUND

• Crum EM, O'Connor WJ, Van Loo L, Valckx M, Stannard SR. Validity and reliability of the Moxy oxygen monitor during incremental cycling exercise. Eur J Sport Sci. 2017 Sep;17(8):1037-1043. doi: 10.1080/17461391.2017.1330899. Epub 2017 May 30.

  PMID: 28557670 BACKGROUND

• Feldmann A, Schmitz R, Erlacher D. Near-infrared spectroscopy-derived muscle oxygen saturation on a 0% to 100% scale: reliability and validity of the Moxy Monitor. J Biomed Opt. 2019 Nov;24(11):1-11. doi: 10.1117/1.JBO.24.11.115001.

  PMID: 31741352 BACKGROUND

• Laveneziana P, Albuquerque A, Aliverti A, Babb T, Barreiro E, Dres M, Dube BP, Fauroux B, Gea J, Guenette JA, Hudson AL, Kabitz HJ, Laghi F, Langer D, Luo YM, Neder JA, O'Donnell D, Polkey MI, Rabinovich RA, Rossi A, Series F, Similowski T, Spengler CM, Vogiatzis I, Verges S. ERS statement on respiratory muscle testing at rest and during exercise. Eur Respir J. 2019 Jun 13;53(6):1801214. doi: 10.1183/13993003.01214-2018. Print 2019 Jun.

  PMID: 30956204 BACKGROUND

• American Thoracic Society/European Respiratory Society. ATS/ERS Statement on respiratory muscle testing. Am J Respir Crit Care Med. 2002 Aug 15;166(4):518-624. doi: 10.1164/rccm.166.4.518. No abstract available.

  PMID: 12186831 BACKGROUND

Study Officials

• Meral BOŞNAK GÜÇLÜ, PhD

  Gazi University

  STUDY DIRECTOR

• Betül Yoleri, MSc

  Gazi University

  STUDY CHAIR

• Mücahit Şahin, Pt

  Gazi University

  PRINCIPAL INVESTIGATOR

• Ece Demirkılınç, Pt

  Gazi University

  PRINCIPAL INVESTIGATOR

• İrem Acar, Pt

  Gazi University

  PRINCIPAL INVESTIGATOR

• Ebrar Tarhan, Pt

  Gazi University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Meral BOŞNAK GÜÇLÜ, Prof. Dr

CONTACT

03122162647; meralbosnak@gazi.edu.tr

Betül YOLERİ, MSc

CONTACT

03122162909; betulyoleri@gazi.edu.tr

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: Outcome assessments are performed by physiotherapists who are not informed of participant allocation. The intervention is not masked to participants or personnel administering the training because the intervention group uses a POWERbreathe device and the control group receives no sham intervention. Group labels will be coded for statistical analysis when feasible.
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Prof. Dr.

Study Record Dates

• First Submitted: August 10, 2026
• First Posted: August 13, 2026
• Study Start: May 1, 2026
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): June 1, 2027
• Last Updated: August 13, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)