Effects of Breathing Training and Nitrate on Exercise at Simulated Altitude

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
• Dietary Supplement
• Nitrate Supplementation
• Inspiratory Muscle Training

Interventions

DEVICE

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.

DEVICE

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

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.

DIETARY_SUPPLEMENT

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.

Sponsors & Collaborators

• Embry-Riddle Aeronautical University

  lead OTHER

Principal Investigators

• Scott K Ferguson, Ph.D. · Embry-Riddle Aeronautical University

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

QUADRUPLE

Model

FACTORIAL

Eligibility

Min Age

18 Years

Max Age

40 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2025-09-01

Primary Completion

2028-08-31

Completion

2028-08-31

Countries

• United States

Study Locations