Acute Effects of Inspiratory Muscle Warm-up on Muscular Performance and Pulmonary Function in Natural Bodybuilders

NCT07390149 | Completed DMC

• 1 other identifier: 2025/0014
• Study Type: interventional
• Target: 27
• Locations: 1 country
• Sites: 1

Brief Summary

The present study aims to investigate the acute effects of inspiratory muscle warm-up (IWU) on 1RM performance in professional natural bodybuilders. The hypothesis is that IWU will lead to an increase in the pressure-generating capacity of the inspiratory muscles, thereby resulting in improved 1RM strength performance. The anticipated findings are expected to contribute not only to the enhancement of maximal strength performance but also to the improvement of exercise efficiency through increased respiratory muscle endurance. It is submitted that these outcomes may ultimately provide insights into the long-term sustainability of professional athletes' performance. Twenty male athletes who had competed in national and international professional natural bodybuilding competitions were recruited for this study. The participants had an average experience in natural bodybuilding of 3.21 years, with a standard deviation of ± 1.44 years, and trained for more than five hours per week. The data collection period commenced in July 2025. The study was designed as a randomized controlled experimental trial. Participants were randomly assigned to two groups by a computerized program at three visits after the trial, based on their first measurement: inspiratory warm-up (IWU) group or control (CON) group.

Conditions

Exercise Physiology; Sports Performance

Keywords

acute interventions; human physiology; inspiratory muscle warm-up; exercise performance; bodybuilders; 1RM

Outcome Measures

Primary Outcomes (2)

• 1RM

  One-Repetition maximum (1RM) bench press performance

  Day 1

• maximal inspiratory pressures (MIP )

  maximal inspiratory pressures (MIP )

  Day 1

Secondary Outcomes (5)

• maximal expiratory pressures (MEP)

  Day 1

• Forced vital capacity (FVC)

  Day 1

• forced expiratory volume in one second (FEV1)

  Day 1

• FEV1/FVC ratio (Tiffeneau index)

  Day 1

• peak expiratory flow (PEF)

  Day 1

Study Arms (2)

IWU

OTHER

The IWU group performed both inspiratory muscle warm-up and standard exercise warm-up.

Other: IWU; Other: Control

Control Group

OTHER

The CON group performed only the standard warm-up.

Other: IWU; Other: Control

Interventions

IWU OTHER

The IWU group performed both inspiratory muscle warm-up and standard exercise warm-up.

Also known as: Inspiratory muscle warm-up

Control Group; IWU

Control OTHER

The CON group performed only the standard warm-up.

Control Group; IWU

Eligibility Criteria

• Age: 18 Years - 35 Years
• Gender Eligibility Details: Male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• They were professional natural bodybuilders with less than three years of experience. ,
• Male professional natural bodybuilders aged 18-35 years
• Full participation in training and matches during the previous 6 months,
• Ability to perform maximal exercise testing

You may not qualify if:

• Individuals were deemed ineligible on the basis of a medical history that included any chronic or acute respiratory disease.
• Individuals were considered ineligible if they were taking any prescription medication that could affect their response to exercise.
• In accordance with the stipulated criteria, individuals were deemed to be ineligible for participation in the study if they had a history of current smoking or had smoked within the past year.
• Individuals were considered ineligible for participation in the study if they had participated in similar studies within the previous six months.
• Prior to participation, all individuals were required to sign a formal waiver, thereby affirming their adherence to the World Anti-Doping Agency Code.

Sponsors & Collaborators

• Gümüşhane Universıty: lead
• Çankırı Karatekin University: collaborator

Study Sites (1)

Gumushane Univetsity

Gümüşhane, Gümüşhane Province, (542) 442-7444, Turkey (Türkiye)

Location

Study Officials

• Coşkun YILMAZ, associate professor

  Gümüşhane Üniversity

  STUDY CHAIR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: OTHER
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: ASSOC. PROF.

Model Details: This study used a randomized, parallel-group design. Participants were randomly allocated to either the inspiratory warm-up (IWU) group or the control (CON) group. All participants completed baseline assessments prior to randomization and remained in their assigned group throughout the study. No crossover between conditions was implemented. Outcome measures were assessed across multiple visits to evaluate pre- and post-intervention responses within each group.

Study Record Dates

• First Submitted: January 18, 2026
• First Posted: February 5, 2026
• Study Start: January 5, 2025
• Primary Completion: April 15, 2025
• Study Completion: January 5, 2026
• Last Updated: May 7, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)