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

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

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.

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.

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%).