Related Experiment Video
Updated: Jan 10, 2026
Supramaximal Intensity Hypoxic Exercise and Vascular Function Assessment in Mice
Published on: March 15, 2019
Effects of Intermittent Hypoxia Protocols on Physical Performance in Trained and Untrained Individuals: An Umbrella
Ayoub Boulares1, Olivier Dupuy2,3, Nicola Luigi Bragazzi4,5,6
1Laboratory Mobility, Aging & Exercise-ER20296, Faculty of Sport Sciences-STAPS, University of Poitiers, Poitiers, France. ayoub.boulares@univ-poitiers.fr.
Background:
Intermittent hypoxia (IH) has emerged as a promising strategy to enhance physical performance by eliciting adaptive responses across cardiovascular, respiratory, and muscular systems. Various IH protocols have been applied in both trained and untrained individuals to improve aerobic capacity, strength, and repeated sprint ability. However, the growing number of systematic reviews and meta-analyses (SRs/MAs) has led to heterogeneous conclusions due to variability in populations, protocols, and outcome measures. This umbrella review aimed to synthesize and critically appraise the available SRs/MAs on the effects of IH protocols on physical performance across different fitness levels.
Methods:
A systematic search, aligned with the PRIOR (Preferred Reporting Items for Overviews of Reviews) guidelines, was conducted across seven electronic databases (PubMed/MEDLINE, Web of Science, Cochrane Database of Systematic Reviews, Scopus, Embase, PsycINFO, and SciELO) from inception to June 2025. Eligible studies included systematic reviews (SRs) with or without meta-analyses (MAs) or network meta-analyses (NMAs) evaluating the effects of intermittent hypoxia protocols on physical performance. Methodological quality was assessed using the AMSTAR-2 tool.
Results:
A total of 22 systematic reviews (14 with meta-analyses, 3 with network meta-analyses) analyzing 487 primary studies and 5,333 participants were included. Intermittent hypoxia (IH) protocols improved both aerobic and anaerobic performance, as well as muscular strength. Live high-train low (LHTL) and live low-train high (LLTH) protocols consistently enhanced V̇O₂max, especially when combined with sea-level training. Anaerobic-focused strategies like repeated sprint training in hypoxia (RSH) and RSH induced by voluntary hypoventilation at low lung volume (RSH-VHL) led to improvements in sprint-fatigue resistance and glycolytic capacity. Intermittent hypoxic interval training (IHIT) and high-intensity interval training (HIIT) under hypoxia showed robust aerobic benefits. However, the magnitude of these effects varied depending on the type of protocol, training status, and hypoxic dose.
Conclusion:
IH is an effective and adaptable strategy to improve aerobic and anaerobic performance, as well as to enhance muscle strength and hypertrophy. These benefits often occur without consistent hematological changes. Future studies should focus on individualized approaches, standardization of terminology, and precise quantification of both hypoxic exposure and training load to optimize outcomes and ensure reproducibility.
Review Registration:
This overview was registered on the International Database of Systematic Review Protocols (PROSPERO ID: CRD42024465481).
Related Concept Videos
01:16Treatment for Pulmonary Arterial Hypertension: Oxygen Therapy for Respiratory Failure
Oxygen therapy is vital in increasing and maintaining blood oxygen levels in PAH patients. As a result, it aids in reducing fatigue,...
01:23Hypoxia
Types of Hypoxia
There are four primary types of hypoxia, each resulting from a different cause:
1. Anemic hypoxia: This type occurs due to insufficient oxygen delivery caused by a lack of red blood cells (RBCs) or RBCs with abnormal or...
01:23Physiological Control of Respiration
Breathing, a seemingly passive process, is regulated by the respiratory center in the brainstem. This center coordinates the involuntary control of respirations, which means it occurs without conscious effort, ensuring a smooth and uninterrupted pattern.
Regulation of Ventilation
The body maintains ventilation by monitoring levels of carbon dioxide (CO2), oxygen (O2), and hydrogen ion concentration (pH) in the arterial blood. Among these factors, the level of CO2 plays a crucial...
01:27Exercise and Muscle Performance
Endurance exercises
Endurance exercises involve running, swimming, or cycling, which require repetitive movements with low force output. When a person engages in endurance exercise, a few noticeable changes occur in their skeletal muscles. For instance, the number of capillaries...
01:19Respiratory Assessment: Purpose and Indications
Objectives and Importance:
The primary goal of respiratory assessment is to evaluate patients at early risk of clinical deterioration. Since respiratory distress often precedes other signs of declining health, breathing patterns and sounds become a...
01:21Acute Respiratory Failure-II
The underlying physiological abnormalities that contribute to hypoxemic respiratory failure include: