Recruiting

RMT & Nitrate

Sponsor:

Embry-Riddle Aeronautical University

Code:

NCT07216755

Conditions

Healthy Adults

Mechanical Ventilation Dependence

Hypoxia

Exercise Training

Exercise Intolerance

Eligibility Criteria

Sex: All

Age: 18 - 40

Healthy Volunteers: Accepted

Interventions

Respiratory Muscle Training (RMT)

Sham Respiratory Muscle Training

Dietary Supplement: Beetroot Juice Concentrate

placebo beverage

Study Details

Brief summary:

This study investigates whether respiratory muscle training (RMT) and dietary nitrate supplementation can improve exercise tolerance under simulated moderate altitude conditions. Exposure to reduced oxygen availability at altitude places additional strain on the cardiovascular and respiratory systems, which may limit endurance performance. By combining RMT-designed to strengthen the muscles involved in breathing-with nitrate therapy, which enhances nitric oxide availability and vascular function, this study aims to determine whether these interventions independently or synergistically improve oxygen delivery, reduce physiological strain, and enhance exercise performance. The findings will help identify non-pharmacological strategies to improve physical performance and tolerance to hypoxia in both clinical and operational environments.

Conditions

Healthy Adults

Mechanical Ventilation Dependence

Hypoxia

Exercise Training

Exercise Intolerance

Study ID

NCT07216755

Start date

Sep 1, 2025

Status verified date

Oct, 2025

Completion date

Aug 31, 2028

Anticipated

Primary completion date

Aug 31, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 40

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Healthy adults between 18 and 40 years old.

Recreationally active (performing ≥3 hours of structured physical activity per week).

Non-smokers for at least the past 6 months.

Free from any known cardiovascular, pulmonary, metabolic, or neuromuscular disease as determined by health screening questionnaire and medical history.

Able to perform cycle ergometer exercise to volitional fatigue.

Willing to abstain from high-nitrate foods and supplements (e.g., beets, spinach, arugula) for 48 hours prior to each testing session.

Able and willing to provide written informed consent and comply with all study procedures.

Exclusion Criteria:

  • Diagnosis of or history of heart disease, hypertension, diabetes, or chronic respiratory disorders (e.g., asthma, COPD).

Current use of medications or supplements known to affect cardiovascular, metabolic, or respiratory function (e.g., beta-blockers, nitrates, stimulants).

Smoking, vaping, or tobacco use within the past 6 months.

Known allergy or intolerance to beetroot products or nitrates.

Participation in another interventional research study within the past 30 days.

Pregnant or breastfeeding women.

Any orthopedic or musculoskeletal limitation preventing safe exercise testing.

Failure to meet inclusion criteria or inability to complete familiarization and baseline testing.

Study Design

Enrollment

80 participants

Anticipated

Allocation

Randomized

Intervention Model

Factorial

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: RMT + Nitrate Supplementation

Participants complete a multi-week respiratory muscle training (RMT) program using a handheld breathing device that provides progressive inspiratory and expiratory resistance. Participants also consume a daily standardized dose of beetroot juice concentrate containing dietary nitrate. This combination is expected to enhance breathing muscle strength, vascular function, and exercise tolerance under simulated altitude.

placebo comparator: Respiratory Muscle Training + Placebo

Participants perform the same RMT program as in Arm 1 but consume a placebo beverage that is visually and taste-matched to the nitrate drink but contains no active nitrate. This group allows assessment of the independent effects of respiratory muscle training.

sham comparator: Sham Respiratory Muscle Training + Nitrate Supplementation

Participants perform sham RMT with a very low resistance load that does not provide a training stimulus, while consuming the active nitrate beverage daily. This group isolates the independent effect of nitrate supplementation on exercise tolerance under hypoxic conditions.

placebo comparator: Sham Respiratory Muscle Training + Placebo

Participants complete sham RMT with minimal breathing resistance and consume a placebo beverage identical in appearance and flavor to the nitrate supplement but containing no active ingredients. This serves as the control condition for comparison with all other intervention groups.

Interventions

Respiratory Muscle Training (RMT)

Participants perform supervised respiratory muscle training (RMT) using a handheld resistive breathing device designed to strengthen the inspiratory and expiratory muscles. Training sessions are conducted 5 days per week for approximately 4-6 weeks. Each session includes a series of resisted breathing maneuvers with progressively increased load as tolerated. The device is calibrated to maintain a constant pressure threshold to ensure consistent training intensity.

Sham Respiratory Muscle Training

Participants use an identical handheld breathing device with minimal resistance, providing no meaningful training stimulus. The training schedule and session duration match those of the active RMT group to maintain participant blinding.

Dietary Supplement: Beetroot Juice Concentrate

Participants consume a standardized dose of concentrated beetroot juice daily for the duration of the training period (approximately 4-6 weeks). The supplement provides a fixed quantity of dietary nitrate known to enhance nitric oxide availability and support vascular and metabolic function during exercise.

placebo beverage

Participants consume a placebo beverage identical in color, taste, and appearance to the nitrate supplement but containing no active nitrate. The beverage is consumed daily following the same schedule as the active supplement.

Primary outcome measure

  • Change in Exercise Tolerance at Simulated Altitude [ Time Frame: Baseline to Post-Intervention (approximately 4-6 weeks) ]

Central Contacts and Locations

Central contacts

Scott Ferguson K Ferguson, Ph.D.

386-226-7381ferguss8@erau.edu

Locations

Embry-Riddle Aeronautical University

Recruiting

Daytona Beach, Florida, United States, 32114

Contacts

Teri Gabriel

1386-226-7179teri.gabriel@erau.edu

Principal Investigator:

Scott K Ferguson, Ph.D.

More Information

Sponsor

Embry-Riddle Aeronautical University

Last update posted

Oct 15, 2025

Last verified

Oct, 2025

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Embry-Riddle Aeronautical University on 2025-10-15.