Hypoxic Environment on EIB and Performance in Race Walkers

NCT07466849 | Completed DMC

• 1 other identifier: 102772025RT102
• Study Type: observational
• Target: 64
• Locations: 1 country
• Sites: 1

Brief Summary

Title: Diagnosis and Impact of Exercise-Induced Bronchoconstriction (EIB) in Athletes During Altitude Training Study Description: We invite you to participate in a research study examining Exercise-Induced Bronchoconstriction (EIB) in athletes. Your participation is entirely voluntary, and you may withdraw at any time without penalty. This study will take place over 2 to 4 months and includes both plains training and altitude training phases. Why is this study being done? The purpose of this study is threefold: To diagnose whether you have EIB (a condition that causes narrowing of the airways during or after exercise). To determine if altitude training induces or worsens EIB. To understand how having (or not having) EIB affects your athletic performance during altitude training. What will you be asked to do? You will be asked to complete the following procedures four times each (with about 2 weeks between each session): Blood Draws: Early morning fasting blood samples (approx. 4 ml from your arm). These are routine tests for the sports team. Exercise Challenge Tests: You will run on a treadmill while wearing a heart rate monitor. This test follows standard safety guidelines (ATS). Your breathing will be tested before exercise and several times after. These are routine tests for the sports team. VO2max Tests: You will run on a treadmill with a breathing mask to measure your maximum oxygen uptake. You will run until exhaustion, following a standardized protocol. Questionnaires: You will wear a heart rate monitor during training and complete short questionnaires about your breathing and how hard you feel you are exercising. How long will participation last? The total study duration is 2-4 months. Individual tasks take between 3 minutes (blood draw) and 50 minutes (exercise challenge). What are the risks? Blood Draw: Possible dizziness, bruising, or discomfort at the needle site. Breathing Tests: You may feel briefly dizzy or tired from blowing hard; this passes quickly. Chest pain is very rare. Exercise Tests: You will experience muscle fatigue and soreness. If you have EIB, you may feel short of breath, wheeze, or feel chest tightness. If symptoms become severe, the test will be stopped. Salbutamol (a standard asthma medication) may be given to relieve symptoms. Using salbutamol as described in this study is permitted under WADA anti-doping rules. What are the benefits? If you do not have EIB, you will receive an educational booklet on preventing EIB. If you do have EIB, you will receive a detailed report for your coach, personalized strategies, and long-term follow-up support. Compensation: If you complete the entire study, you will receive a commemorative gift. No compensation is provided for partial participation. Contact for Questions: If you have any questions about the study or your rights as a participant, please contact the principal investigator listed on the consent form or email the Shanghai Sports University Research Ethics Committee at lunli@sus.edu.cn.

Conditions

Exercise-induced Bronchoconstriction (EIB)

Keywords

Exercise-induced bronchoconstriction (EIB); Hypoxia; High altitude; Prevalence; Athlete

Outcome Measures

Primary Outcomes (2)

• Incidence of Exercise-Induced Bronchoconstriction

  The incidence of EIB is defined as the percentage of athletes diagnosed with a positive EIB status. A positive diagnosis is confirmed if there is a fall in Forced Expiratory Volume in 1 second (FEV1) of ≥10% from the pre-exercise baseline value, following a standardized laboratory bronchial provocation test. Lung function is measured pre-exercise and at 1, 3, 5, 7, 10, and 15 minutes post-exercise.

  Week 3 (baseline), Week 5 (initial altitude training), and Week 12 (final altitude training)

• Maximum Percentage Fall in FEV1 (FEV1 Decline Rate)

  The maximum percentage decrease in FEV1 following the laboratory bronchial provocation test, compared to the pre-exercise baseline value. The decline rate is calculated to assess the severity of exercise-induced airway narrowing.

  Week 3 (baseline), Week 5 (initial altitude training), and Week 12 (final altitude training)

Secondary Outcomes (36)

• Serum Levels of Clara Cell Protein 16

  Week 3 (baseline), Week 5 (initial altitude training), and Week 12 (final altitude training)

• Serum Interleukin-6 (IL-6) Concentration

  Week 3 (baseline), Week 5 (initial altitude training), and Week 12 (final altitude training)

• Serum level of Immunoglobulin E

  Week 3 (baseline), Week 5 (initial altitude training), and Week 12 (final altitude training)

• White blood cell count

  Week 3 (baseline), Week 5 (initial altitude training), and Week 12 (final altitude training)

• Neutrophil count

  Week 3 (baseline), Week 5 (initial altitude training), and Week 12 (final altitude training)

Study Arms (1)

Race Walking Athletes

A single cohort of 64 provincial-level race walking athletes (35 males, 29 females). The cohort undergoes baseline and follow-up testing at sea level (0-153m), followed by an 8-week high-altitude training program (1880-2030m). They are assessed for lung function and risk of exercise-induced bronchoconstriction (EIB) across several distinct testing stages

Other: High-Altitude Training & Hypoxic Environment Exposure

Interventions

High-Altitude Training & Hypoxic Environment Exposure OTHER

Athletes underwent an 8-week race walking training program in a high-altitude environment (1880-2030m). This exposure is compared to a baseline period at sea level (0-153m)

Race Walking Athletes

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

This study aims to enroll active race walking athletes with a minimum technical grade of National First-Class (≥ Tier 3). The target population represents well-trained endurance athletes currently preparing for or competing in national-level events. Participants are expected to be free from injury and in a consistent training macrocycle to ensure the validity of the physiological assessments.

You may qualify if:

• Only athletes who meet the following conditions simultaneously can be included in this study:
• Engaged in race walking specialized training;
• The athlete's technical grade reaches the national first-class standard or above (the athlete's level level is ≥ Tier 3);
• Regular professional training is still maintained at present.

You may not qualify if:

• Presence of chronic cardiopulmonary diseases (e.g., chronic obstructive pulmonary disease, pulmonary heart disease, known structural heart disease) or other significant medical conditions (e.g., uncontrolled hypertension, depression) that could confound respiratory test results or pose a risk during intense exercise;
• Known hypersensitivity to hypoxia or history of severe altitude sickness (e.g., high-altitude pulmonary edema \[HAPE\], high-altitude cerebral edema \[HACE\]);
• Sickle cell trait or disease;
• History of chest surgery within the preceding 6 months;
• Any active lung infection (e.g., pneumonia, bronchitis) or systemic infection within 3 weeks before the examination;
• Cessation of regular training for 2 or more weeks immediately before the examination, to ensure participants were in their typical training state;
• Experience of a moderate or severe upper respiratory tract infection (e.g., common cold) within the week preceding the examination;
• Individuals who reported chest pain or experienced syncope (fainting) during the spirometry maneuver;
• Individuals who were unable to understand the test instructions or unwilling to cooperate fully with the testing procedures, as determined by the research staff.

Sponsors & Collaborators

• Shanghai University of Sport: lead

Study Sites (1)

Chongqing Institute of Sports Science

Chongqing, China

Location

MeSH Terms

Conditions

Hypoxia; Altitude Sickness

Condition Hierarchy (Ancestors)

Signs and Symptoms, Respiratory; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Respiration Disorders; Respiratory Tract Diseases

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: February 22, 2026
• First Posted: March 12, 2026
• Study Start: July 16, 2025
• Primary Completion: October 16, 2025
• Study Completion: October 18, 2025
• Last Updated: March 12, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)