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Influence of Graded Hypercapnia on Endurance Exercise Performance

Primary Purpose

Hypercapnia

Status
Completed
Phase
Not Applicable
Locations
United States
Study Type
Interventional
Intervention
Inspired gas
Sponsored by
United States Army Research Institute of Environmental Medicine
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional other trial for Hypercapnia

Eligibility Criteria

18 Years - 45 Years (Adult)All SexesAccepts Healthy Volunteers

Inclusion Criteria:

  • Male or female, age 18-45
  • In good health as determined by medical screening
  • Passed his/her most recent Army Combat Fitness Test (ACFT) (Military Volunteers Only) or performs aerobic exercise at least 2 times per week and able to complete two mile run in ≤ 21 minutes (Civilian Volunteers)
  • Willing to not participate in any exercise or drink alcoholic beverages for 24 hours before each study visit.
  • Willing to not take part in any strenuous exercise in the 36 hours before each visit.
  • Willing not to drink caffeine or eat food until after testing on familiarization and performance testing visits (visits 2-6).
  • Willing to maintain a similar dietary pattern in the 2 days before each familiarization and performance visits.
  • Have supervisor approval if permanent party military or a federal employee at U.S. Army Natick Soldier System Center
  • Able to speak and read English fluently

Exclusion Criteria:

  • Females who are pregnant or planning to become pregnant during the study
  • Taking dietary supplements, prescriptions, or over the counter medication, other than a contraceptive (unless approved by medical staff & PI)
  • Musculoskeletal injuries that compromise ability to run on a treadmill
  • Abnormal blood count, presence of abnormal blood chemicals (hemoglobin S or sickle cell traits)
  • Smokers or tobacco/nicotine users (unless have quit > 1 month prior)
  • Any history of asthma
  • Current or recent respiratory tract or sinus infections (< 1 month prior)
  • Allergy to skin adhesive
  • Any history of migraine or recurrent headaches
  • Any history of panic disorder
  • Blood donation in the previous 8 weeks
  • Positive Covid-19 test within the last month

Sites / Locations

  • USARIEM

Arms of the Study

Arm 1

Arm 2

Arm 3

Arm Type

Experimental

Experimental

Sham Comparator

Arm Label

4% CO2

2% CO2

0% CO2

Arm Description

Inspired gas containing 4% CO2, 21% O2, balance N2

Inspired gas containing 2% CO2, 21% O2, balance N2

Inspired gas containing 0% CO2, 21% O2, balance N2

Outcomes

Primary Outcome Measures

2 mile self-paced treadmill time trial performance
Time to complete self-paced 2 mile treadmill time trial (min:sec)

Secondary Outcome Measures

Ventilation rate
Ventilation rate will be assessed using a pneumotachometer [L/min]
Oxygen consumption
Oxygen consumption will be assessed using computerized indirect calorimetry [ml/kg/min]
Heart rate
Heart rate will be assessed using telemetry [beats per min]
Arterialized capillary pH
Arterialized capillary pH will be assessed using a blood gas analyzer [Unitless]
Arterialized capillary pCO2
Arterialized capillary pCO2 will be assessed using a blood gas analyzer [mmHg]
Arterialized capillary HCO3
Arterialized capillary HCO3 will be assessed using a blood gas analyzer [mEq/L]
Rating of perceived exertion
Rating of perceived exertion will be assessed using Borg's 6-20 scale [AU]
Dyspnea
Rating of perceived dyspnea will be assessed using Borg's 0-10 scale [AU]
Leg discomfort
Rating of perceived leg discomfort will be assessed using Borg's 0-10 scale [AU]
Headache
Headache will be assessed using a visual analog scale [AU]
Breathing descriptors
Breathing descriptors will be assessed by having participants check statements that apply to their breathing (e.g., breathing out requires more effort) [unitless]

Full Information

First Posted
October 13, 2021
Last Updated
May 24, 2022
Sponsor
United States Army Research Institute of Environmental Medicine
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1. Study Identification

Unique Protocol Identification Number
NCT05116397
Brief Title
Influence of Graded Hypercapnia on Endurance Exercise Performance
Official Title
Influence of Graded Hypercapnia on Endurance Exercise Performance
Study Type
Interventional

2. Study Status

Record Verification Date
May 2022
Overall Recruitment Status
Completed
Study Start Date
September 10, 2021 (Actual)
Primary Completion Date
April 14, 2022 (Actual)
Study Completion Date
April 14, 2022 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Sponsor
Name of the Sponsor
United States Army Research Institute of Environmental Medicine

4. Oversight

Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Data Monitoring Committee
No

5. Study Description

Brief Summary
The aim of this randomized, single-blind, placebo-controlled crossover trial is to determine the effects of graded hypercapnia (0, 2, and 4% inspired CO2) on endurance performance. Twelve healthy and fit young adults (men and women) will complete this study. Participants will perform experimental trials on 3 separate days (one each breathing 0%, 2%, and 4% inspired CO2-all with normal 21% oxygen). During each trial, they will perform 10 minutes of submaximal treadmill walking exercise and then complete a self-paced 2-mile treadmill run time-trial.
Detailed Description
Participants will undergo baseline measurements of pulmonary function and maximal oxygen uptake (VO2max). They will then complete two familiarization trials, with 10 minutes of submaximal exercise (~40%VO2max) followed by a self-paced 2-mile treadmill time trial. Lastly, they will complete three experimental trials, repeating the same submaximal and time-trial exercise procedures while breathing the test gas (0%, 2%, or 4% CO2-all with normal 21% oxygen). During the experimental trials, arterialized capillary blood samples will be collected at rest breathing room air, at rest breathing the test gas, and during submaximal exercise at 40% VO2max breathing the test gas. The primary outcome is 2-mile treadmill time-trial performance. Secondary outcomes include ventilation, metabolic rate, heart rate, arterialized capillary pH/PCO2/HCO3, perceived exertion, dyspnea, leg discomfort, breathing descriptors, and headache ratings.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Hypercapnia

7. Study Design

Primary Purpose
Other
Study Phase
Not Applicable
Interventional Study Model
Crossover Assignment
Model Description
Randomized, single-blinded crossover design
Masking
Participant
Masking Description
Single-blinded
Allocation
Randomized
Enrollment
15 (Actual)

8. Arms, Groups, and Interventions

Arm Title
4% CO2
Arm Type
Experimental
Arm Description
Inspired gas containing 4% CO2, 21% O2, balance N2
Arm Title
2% CO2
Arm Type
Experimental
Arm Description
Inspired gas containing 2% CO2, 21% O2, balance N2
Arm Title
0% CO2
Arm Type
Sham Comparator
Arm Description
Inspired gas containing 0% CO2, 21% O2, balance N2
Intervention Type
Other
Intervention Name(s)
Inspired gas
Intervention Description
Inspired gas content
Primary Outcome Measure Information:
Title
2 mile self-paced treadmill time trial performance
Description
Time to complete self-paced 2 mile treadmill time trial (min:sec)
Time Frame
30 minutes
Secondary Outcome Measure Information:
Title
Ventilation rate
Description
Ventilation rate will be assessed using a pneumotachometer [L/min]
Time Frame
30 minutes
Title
Oxygen consumption
Description
Oxygen consumption will be assessed using computerized indirect calorimetry [ml/kg/min]
Time Frame
30 minutes
Title
Heart rate
Description
Heart rate will be assessed using telemetry [beats per min]
Time Frame
30 minutes
Title
Arterialized capillary pH
Description
Arterialized capillary pH will be assessed using a blood gas analyzer [Unitless]
Time Frame
30 minutes
Title
Arterialized capillary pCO2
Description
Arterialized capillary pCO2 will be assessed using a blood gas analyzer [mmHg]
Time Frame
30 minutes
Title
Arterialized capillary HCO3
Description
Arterialized capillary HCO3 will be assessed using a blood gas analyzer [mEq/L]
Time Frame
30 minutes
Title
Rating of perceived exertion
Description
Rating of perceived exertion will be assessed using Borg's 6-20 scale [AU]
Time Frame
30 minutes
Title
Dyspnea
Description
Rating of perceived dyspnea will be assessed using Borg's 0-10 scale [AU]
Time Frame
30 minutes
Title
Leg discomfort
Description
Rating of perceived leg discomfort will be assessed using Borg's 0-10 scale [AU]
Time Frame
30 minutes
Title
Headache
Description
Headache will be assessed using a visual analog scale [AU]
Time Frame
30 minutes
Title
Breathing descriptors
Description
Breathing descriptors will be assessed by having participants check statements that apply to their breathing (e.g., breathing out requires more effort) [unitless]
Time Frame
30 minutes

10. Eligibility

Sex
All
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
45 Years
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Inclusion Criteria: Male or female, age 18-45 In good health as determined by medical screening Passed his/her most recent Army Combat Fitness Test (ACFT) (Military Volunteers Only) or performs aerobic exercise at least 2 times per week and able to complete two mile run in ≤ 21 minutes (Civilian Volunteers) Willing to not participate in any exercise or drink alcoholic beverages for 24 hours before each study visit. Willing to not take part in any strenuous exercise in the 36 hours before each visit. Willing not to drink caffeine or eat food until after testing on familiarization and performance testing visits (visits 2-6). Willing to maintain a similar dietary pattern in the 2 days before each familiarization and performance visits. Have supervisor approval if permanent party military or a federal employee at U.S. Army Natick Soldier System Center Able to speak and read English fluently Exclusion Criteria: Females who are pregnant or planning to become pregnant during the study Taking dietary supplements, prescriptions, or over the counter medication, other than a contraceptive (unless approved by medical staff & PI) Musculoskeletal injuries that compromise ability to run on a treadmill Abnormal blood count, presence of abnormal blood chemicals (hemoglobin S or sickle cell traits) Smokers or tobacco/nicotine users (unless have quit > 1 month prior) Any history of asthma Current or recent respiratory tract or sinus infections (< 1 month prior) Allergy to skin adhesive Any history of migraine or recurrent headaches Any history of panic disorder Blood donation in the previous 8 weeks Positive Covid-19 test within the last month
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Benjamin J Ryan, Ph.D.
Organizational Affiliation
United States Army Research Institute of Environmental Medicine
Official's Role
Principal Investigator
Facility Information:
Facility Name
USARIEM
City
Natick
State/Province
Massachusetts
ZIP/Postal Code
01760
Country
United States

12. IPD Sharing Statement

Plan to Share IPD
No

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Influence of Graded Hypercapnia on Endurance Exercise Performance

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