The Effect of Inspiratory Muscle Warm-up on Decreased Diffusing Capacity for Carbon Monoxide After Maximal Exercise in Athletes

Official title

The Effect of Inspiratory Muscle Warm-up on Decreased Diffusing Capacity for Carbon Monoxide After Maximal Exercise in Athletes: a Randomized, Placebo-controlled, Double-blind and Crossover Study

Overview

This study aims to examine the effects of inspiratory muscle warm-up (IMW) on the gas exchange capacity of the lungs (DLCO) and its potential contribution to recovery and athletic performance in elite athletes from various disciplines. The study hypothesizes that the decline in respiratory muscle capacity following high-intensity exercise, which negatively affects ventilation, diffusion, and oxygen transport, may be ameliorated through specific IMW protocol. A placebo-controlled, randomized, crossover, and double-blind design will be utilized, involving 28 elite male athletes from endurance, power, skill-based, and mixed disciplines. Participants will complete three warm-up protocols: General Warm-up (GW), General Warm-up combined with IMW at 40% resistance intensity (GW+IMW40%), and a placebo condition (GW+IMWplacebo). Measurements will include respiratory muscle strength, DLCO (assessed at post-2, 30, 60, 90, and 120 minutes), respiratory function, and cardiorespiratory parameters during maximal exercise. This study is unique as it aims to detail the micro-level effects of IMW on pulmonary diffusion mechanisms and performance outcomes, providing novel insights into the ameliorative effects of IMW on respiratory function post-exercise. Additionally, it seeks to expand understanding of the mechanistic basis of IMW's benefits on both pulmonary diffusion capacity and athletic performance.

Detailed description

STUDY DESIGN This study will employ a placebo-controlled, randomized, crossover, and double-blind research design to evaluate the effects of three warm-up conditions: Control, Placebo 15%, and IMW 40%. Athletes will be randomly assigned to the conditions using a crossover approach, ensuring that all participants will experience each protocol on separate days.

The warm-up protocols will include:

General Warm-up (Control): A standard warm-up without resistance. IMW 40%: A general warm-up combined with inspiratory muscle warm-up at 40% resistance intensity.

Placebo 15%: A general warm-up combined with inspiratory muscle warm-up (placebo) at 15% resistance intensity.

Blinding will be maintained for both participants and researchers. Participants will be informed that the study aims to investigate various warm-up types, while the true purpose will remain concealed. This design will ensure reliability and minimize bias in the data to be collected.

Interventions

• Other General warm-up
  The General Warm-up (Control) protocol will consist of activities such as running and dynamic, active, and passive movements, adapted to suit the varied sports disciplines included in the study. These exercises will align with the principles of elevation, activation, and mobilization, aiming to enhance mobility across key muscle groups, from the arms and shoulders to the lower back and legs. Each session will include clear demonstrations to ensure proper technique and pacing, with participants p
• Other Inspiratory muscle warm-up (Placebo - %15)
  The placebo inspiratory muscle warm-up protocol will utilize the POWERbreathe® device at 15% of maximal inspiratory pressure (MIP). This placebo protocol will consist of two sets of 30 breaths, separated by a 60-second rest interval, with participants seated and wearing a nose clip. Proper technique will be taught during a prior familiarization session, and participants will be closely monitored during testing to ensure accurate execution. This protocol is designed to function as a placebo, effe
• Other Inspiratory muscle warm-up (%40 IMW)
  This study will implement a respiratory muscle warm-up protocol at 40% of maximal inspiratory pressure (MIP) using the POWERbreathe® device, as this intensity is considered optimal for effectively stimulating respiratory muscles. The protocol will consist of two sets of 30 breaths, with a 60-second rest period between sets, conducted while participants are seated and wearing a nose clip. Training for proper technique will be provided during the familiarization session, and participants will be c

Primary outcome measures

• Lung Carbon Monoxide Diffusion Capacity (DLCO) [Time frame: Pre intervention and immediately post intervention]
• Pulmonary Function (FVC) [Time frame: Pre intervention and immediately post intervention]
• Pulmonary Function (SVC) [Time frame: Pre intervention and immediately post intervention]
• Pulmonary Functions (MVV) [Time frame: Pre intervention and immediately post intervention]
• Respiratory Muscle Strength [Time frame: Pre intervention and immediately post intervention]
• Bicycle ergometer and Maximal Aerobic Capacity (VO2max) [Time frame: Pre intervention and immediately post intervention]

Eligibility criteria

Inclusion criteria

• Age between 18-24 years.
• A training history of at least six years.
• Regular training frequency of at least four sessions per week.

Exclusion criteria

• History of smoking.
• History of physical disability or acute respiratory or cardiovascular disease within the past three months.
• Diagnosis of SARS-CoV-2 within the past three months.
• Pulmonary function measurements outside the normal clinical range (≤ 80%).

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Crossover

Masking

Double blind

Primary purpose

Other

Study locations

Center list to be confirmed — check the primary protocol.

Identifiers

NCT: NCT06751511 · 2023/473

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗