Impact of Respiratory Muscle Training and Nitrate Therapy on Exercise Tolerance in Simulated Altitude
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 发起方
- 入组人数
- 80
- 试验地点
- 1
- 主要终点
- Change in Exercise Tolerance at Simulated Altitude
研究概览
简要总结
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.
详细描述
This study is designed to test whether two non-drug interventions-respiratory muscle training (RMT) and dietary nitrate supplementation-can improve exercise performance and tolerance when oxygen levels are lower than normal, such as at moderate altitude.
When people exercise in low-oxygen environments, the body must work harder to deliver enough oxygen to the muscles. This can lead to faster fatigue and reduced endurance. Strengthening the breathing muscles and improving blood vessel function may help the body adapt better to these conditions. This study will explore how RMT and nitrate supplementation, either alone or together, affect breathing, blood flow, and exercise capacity.
Why This Study Is Being Done:
Researchers want to find out whether strengthening the breathing muscles through RMT, and increasing nitric oxide in the body through nitrate (found naturally in beetroot juice), can make it easier to exercise when oxygen is limited. Nitric oxide helps widen blood vessels and improve oxygen delivery to muscles. The goal is to learn if these approaches can help healthy adults perform better in low-oxygen conditions and whether combining them produces a greater benefit than using either one alone.
Who Will Participate:
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Factorial
- 主要目的
- Basic Science
- 盲法
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 40 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •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.
排除标准
- •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.
研究组 & 干预措施
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.
干预措施: Respiratory Muscle Training (RMT) (Device)
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.
干预措施: Dietary Supplement: Beetroot Juice Concentrate (Dietary Supplement)
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.
干预措施: Respiratory Muscle Training (RMT) (Device)
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.
干预措施: placebo beverage (Dietary Supplement)
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.
干预措施: Sham Respiratory Muscle Training (Device)
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.
干预措施: Dietary Supplement: Beetroot Juice Concentrate (Dietary Supplement)
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.
干预措施: Sham Respiratory Muscle Training (Device)
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.
干预措施: placebo beverage (Dietary Supplement)
结局指标
主要结局
Change in Exercise Tolerance at Simulated Altitude
时间窗: Baseline to Post-Intervention (approximately 4-6 weeks)
Exercise tolerance will be measured as the time to exhaustion during a graded cycling exercise test performed under simulated moderate altitude conditions (\~2,500-3,000 meters). Tests will be conducted before and after the 4-6 week intervention period. The measure reflects overall improvements in aerobic performance and fatigue resistance following respiratory muscle training, nitrate supplementation, or their combination.
次要结局
未报告次要终点
研究者
Scott Kohman Ferguson
Assistant Professor
Embry-Riddle Aeronautical University