The Effect of Respiratory Muscle Warm-up on Pulmonary Diffusion Capacity in Athletes

Effects of Inspiratory Muscle Warm-up on Diffusion Capacity for Carbon Monoxide, Cardiorespiratory, Perceptual and Performance Outcomes During High-intensity Exercise in Elite Athletes from Different Disciplines: a Randomized, Placebo-controlled, Double-blind and Crossover Study

Several studies suggest that inspiratory muscle warm-up (IMW) could potentially affect exercise performance; however, its mechanistic basis is still unclear. The aim of this study was to examine the effect of IMW on lung diffusing capacity for carbon monoxide, cardiorespiratory, perceptual and performance outcomes in elite athletes from different disciplines.

The aim of this study is to evaluate the effects of IMW on diffusion capacity for carbon monoxide, cardiorespiratory, perceptual and performance outcomes during high-intensity exercise in elite athletes from different disciplines. The study will be conducted using a randomized, placebo-controlled, double-blind and crossover study experimental design involving 35 athletes from various sports disciplines, including endurance, strength, skill-based, and mixed disciplines.

Participants will attend the laboratory on four separate occasions. During the first visit, they will be informed about the study and familiarized with the application and measurement procedures. In the second visit, a general warm-up will be performed. During the third and fourth visits, IMW (IMW40% or IMW placebo) protocols will be applied in addition to the general warm-up. Measurements of DLCO, pulmonary function tests, respiratory muscle strength, and gas analysis during maximal aerobic exercise will be collected both before and after the warm-up protocols.

A. STUDY DESING 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 respiratory muscle exercise at 40% resistance.

Placebo 15%: A general warm-up combined with placebo respiratory muscle exercise at 15% resistance.

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.

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%).