Diaphragm Function and Diver Endurance - Clinical Trial

What is the Purpose of this Study?


We are doing this study to find out if a new method to train the breathing muscles is effective. We want to know if this training can improve how well people can move and exercise underwater while connected to oxygen (i.e., while diving).

Specifically, we want to test whether or not these methods can increase personal endurance and reduce excessive rise in blood carbon dioxide during underwater exercise in divers. We will also look at how oxygen and carbon dioxide enters and leaves blood cells and how it affects exercise capacity.

What is the Condition Being Studied?

Underwater Breathing and Exercise

Who Can Participate in the Study?

Key Eligibility

People ages 18-45 who:
- Are in good general health
- Do not smoke
- Do not have heart or lung disease
- Are not pregnant

For more information please contact the study team at DIAPHRAGMstudy@duke.edu.

Age Group

What is Involved?


In this study, we will test the effect of daily breathing muscle training on breathing muscle performance and underwater exercise endurance during a dive to 55 feet of sea water. Breathing muscle training will require 30 minutes every day, 5 days per week for 4 weeks. During this training, each participant will breathe either air or a very low dose of carbon monoxide, which is safe and believed to improve muscle function.

Before and after the endurance test (which usually takes around 2 hours), there will be some tests to measure breathing capabilities. During the endurance test blood samples will be obtained.

Study participants are paid for their time.

Study Details

Full Title
Diaphragm Function, Chemosensitivity and Endurance in Exercising Divers
Principal Investigator
Protocol Number
IRB: PRO00107090
NCT: NCT04679402
Phase I/II
Enrollment Status
Open for Enrollment