Breathing Training to Improve Human Performance at High Altitude

Mountain Sickness Acute Clinical Trial

Official title:

Breathing Training to Improve Human Performance at High Altitude

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03530163
• Other study ID #: 18-0464
• Status: Completed
• Phase: N/A
• Start date: August 9, 2018
• Est. completion date: January 15, 2020

Study information

• Verified date: April 2022
• Source: University of Colorado, Denver
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Individuals traveling to altitudes above 8,000 feet may suffer from impaired exercise and cognitive performance, and acute mountain sickness (AMS). Decreased barometric pressure, which leads to low blood oxygen levels, is the primary cause of these disorders. Symptoms of AMS are characterized by headache, nausea, vomiting, dizziness, fatigue, and difficulty sleeping. The goal of this research is to identify whether Respiratory Muscle Training will improve physical and cognitive performance, and reduce the symptoms of AMS, at simulated high altitude.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 28
• Est. completion date: January 15, 2020
• Est. primary completion date: January 15, 2020
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Male
• Age group: 18 Years to 45 Years

Eligibility

Inclusion Criteria:

• Healthy

• Men, ages 18-45 who are able to achieve at least 3.5 watts/kg of body weight during the peak oxygen uptake test

Exclusion Criteria:

• Less than 18 years old

• Greater than 45 years old

• Have a body mass index greater than or equal to 30

• Have been recent smokers (tobacco or e-cigarettes)

• Current recreational or medical marijuana users

• Currently taking any medication (over-the-counter or prescription) or herbal supplements

• Participants who are unable to tolerate drinking only two, 6-ounce caffeinated beverages per day of the study

• Participants who are legally blind

• Participants who have been to altitudes above Denver (1609m or 5280ft), including air travel, in the 3 weeks prior to the start of the study or with plans to do so during the study

• Participants who have suffered a significant head injury, have anemia or sickle cell trait or disease, have active peptic ulcer disease, diabetes, hypertension, heart disease, HIV/AIDS, glaucoma, kidney disease, liver disease/cirrhosis, adrenal gland failure, hyponatremia/hypokalemia, tuberculosis

• Participants who have a current herpes infection or any other current type of viral or bacterial infection

• Participants with seizure disorders or history of migraines

Related Conditions & MeSH terms

• Altitude Sickness
• Mountain Sickness Acute

Intervention

Device:
• Respiratory Muscle Training
Subjects will breathe through a custom isocapnic Respiratory Muscle Training method developed in-house. The initial breathing frequency will be 30 breaths per minute. Subsequent sessions will begin with 20 minutes of breathing at the highest rate attained on the previous training day. During the last 10 minutes of each session, breathing rate will increase by 1-2 breaths/min.
• Sham Breathing Training
Each subject in the sham group will be prompted to hold his breath for 10 seconds every 30 seconds (two times each minute) while breathing on a circuit visibly identical to that used in Respiratory Muscle Training. The subject will breathe ambient air normally after each breath hold. Each sham session will last 30 minutes total.

Locations

Country	Name	City	State
United States	Altitude Research Center	Aurora	Colorado

Sponsors (2)

Lead Sponsor	Collaborator
University of Colorado, Denver	United States Department of Defense

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in exercise performance during acute simulated high-altitude exposure as measured by a peak oxygen uptake test and time to complete a 720kJ (40km) time trial on a Velotron cycle ergometer.	Determine whether Respiratory Muscle Training performed 3x a week for 30 minutes per session is effective in improving exercise performance during acute simulated high-altitude exposure.	Baseline and during acute simulated high-altitude exposure. (2 days, 12 hours per day)
Primary	Change in cognitive function during acute simulated high-altitude exposure as measured by the DANA cognitive test battery.	Determine whether Respiratory Muscle Training performed 3x a week for 30 minutes per session improves cognitive function during simulated high-altitude exposure.	Baseline and during acute simulated high-altitude exposure. (2 days, 12 hours per day)
Primary	Change in incidence and severity of acute mountain sickness during acute simulated high-altitude exposure as determined by the Lake Louise Questionnaire (a diagnostic survey of acute mountain sickness).	Determine whether Respiratory Muscle Training performed 3x a week for 30 minutes per session is effective in reducing incidence and severity of AMS during acute simulated high-altitude exposure.	Baseline and during acute simulated high-altitude exposure. (2 days, 12 hours per day)