Elevation Training Masks: Purpose, Science, and Limitations in Workouts

Why do people wear oxygen masks while working out?

The devices commonly referred to as "oxygen masks" in a workout context are actually elevation training masks or hypoxic masks, designed to restrict airflow and simulate the physiological challenges of high-altitude training, not to deliver supplemental oxygen. While they can strengthen respiratory muscles, scientific evidence supporting their ability to induce systemic altitude-like adaptations (like increased red blood cell count) is largely inconclusive or negative.

What Are These "Oxygen Masks" Actually?

The term "oxygen mask" is a common misnomer when referring to devices worn during exercise. An actual oxygen mask delivers supplemental oxygen, which would typically enhance performance rather than challenge it. The masks seen in gyms or worn by athletes are, in fact, elevation training masks (also known as hypoxic masks or altitude masks). These devices work by restricting the amount of air an individual can inhale and exhale, thereby increasing the effort required to breathe.

• Common Misconception: The visual similarity to medical oxygen masks leads to the incorrect assumption that they are supplying oxygen.
• Actual Mechanism: These masks contain valves or adjustable resistance caps that reduce the cross-sectional area for airflow, making each breath more challenging. This creates a sensation of "air hunger" and forces the respiratory muscles to work harder.

The Theory Behind Elevation Training Masks: Simulating Altitude

The primary theoretical premise behind wearing an elevation training mask is to mimic the physiological effects of training at high altitudes without physically being there. At higher altitudes, the atmospheric pressure is lower, meaning there is less partial pressure of oxygen (PO2). This state, known as hypoxia, challenges the body to adapt to a reduced oxygen supply.

• Physiological Adaptations at True Altitude:
  • Increased Erythropoietin (EPO) Production: The kidneys release EPO, stimulating the bone marrow to produce more red blood cells, which carry oxygen.
  • Enhanced Oxygen-Carrying Capacity: More red blood cells mean a greater ability to transport oxygen from the lungs to working muscles.
  • Improved Ventilatory Drive: The body becomes more efficient at breathing.
  • Increased Capillary Density: More tiny blood vessels are formed, improving oxygen delivery to tissues.
  • Mitochondrial Efficiency: Cells become better at utilizing oxygen for energy production.

These adaptations collectively lead to improved aerobic capacity and endurance performance when returning to sea level.

How Elevation Masks Attempt to Replicate Altitude Training

Elevation training masks aim to induce some of these adaptations by creating a hypoxic-like environment, primarily by increasing the work of breathing.

• Respiratory Muscle Training (RMT): By restricting airflow, the masks force the diaphragm and intercostal muscles (muscles involved in breathing) to exert more force. This can lead to increased strength and endurance of these muscles, potentially delaying respiratory muscle fatigue during intense exercise.
• Increased Ventilatory Demand: The body's respiratory system works harder to maintain adequate oxygen levels, which can improve breathing efficiency.
• Simulated Hypoxia (Local vs. Systemic): While the masks create a localized hypoxic environment within the respiratory system due to reduced airflow, they generally do not create the systemic, whole-body hypoxia that true high-altitude exposure does. True altitude training reduces the partial pressure of oxygen in the ambient air, leading to lower oxygen saturation in the blood. Elevation masks primarily reduce the volume of air inhaled, not necessarily the percentage of oxygen in that air.

The Science: Do They Actually Work?

Despite their popularity, the scientific evidence supporting the efficacy of elevation training masks in replicating true altitude training benefits is largely limited and, in many cases, contradictory or negative.

• Limited Systemic Adaptations: Most research indicates that elevation masks do not significantly increase erythropoietin (EPO) levels, red blood cell count, or overall oxygen-carrying capacity of the blood, which are hallmarks of true altitude training.
• Primary Benefit: Respiratory Muscle Strengthening: The most consistent finding is that these masks can improve respiratory muscle strength and endurance. This can lead to a reduced perception of effort during exercise and potentially delay fatigue of the breathing muscles, allowing an athlete to maintain higher intensity for longer.
• No Significant VO2 Max Improvements: Studies often show no significant improvement in maximal oxygen uptake (VO2 max) or endurance performance directly attributable to the masks beyond what could be achieved with regular training.
• Distinction from True Hypoxia: The key difference lies in the nature of the challenge. True altitude training reduces the amount of oxygen available in each breath. Elevation masks reduce the volume of air you can take in and increase the resistance to breathing, making the act of breathing harder, but not necessarily reducing the systemic oxygen saturation to the same degree as actual altitude.

Who Uses Them and Why?

Elevation training masks are used by a variety of individuals, often for different reasons.

• Athletes (Endurance and Combat Sports): Some endurance athletes and those in combat sports (e.g., MMA, boxing) use them hoping for an edge in cardiovascular endurance or to build mental toughness. They might believe, incorrectly, that the masks are delivering the full benefits of altitude training.
• Recreational Lifters and Fitness Enthusiasts: Others use them for the perceived challenge, the novelty, or the "hardcore" aesthetic. They might feel that the increased effort in breathing adds another layer of intensity to their workouts.
• Specific Respiratory Training: In some specialized contexts, they might be used as a tool for targeted respiratory muscle training, similar to how inspiratory muscle trainers are used.

Potential Risks and Considerations

While generally safe for healthy individuals, there are some considerations and potential downsides to using elevation training masks:

• Discomfort and Anxiety: The sensation of restricted breathing can be uncomfortable, induce claustrophobia, or even cause panic in some individuals.
• Performance Impairment: Wearing the mask during a workout can significantly reduce your ability to perform at your maximum capacity due to the increased work of breathing and potential for reduced oxygen delivery to working muscles. This could hinder the quality of your training sessions.
• Difficulty Assessing Effort: The perceived exertion can be artificially inflated by the breathing restriction, making it harder to accurately gauge your true physiological output and adjust your training intensity.
• Hygiene: If masks are shared or not properly cleaned, they can become a breeding ground for bacteria and viruses.
• No Substitute for Altitude: It's crucial to understand that these masks are not a substitute for actual living or training at high altitudes, which produces distinct and more profound physiological adaptations.

Conclusion: Are They Worth It?

For most individuals seeking to improve their aerobic capacity or endurance performance, the scientific evidence suggests that elevation training masks offer limited, if any, benefits beyond what can be achieved through well-structured conventional training.

• Primary Utility: Their most substantiated benefit lies in strengthening respiratory muscles, which can enhance breathing efficiency and delay respiratory fatigue.
• Alternative and Superior Methods: If your goal is to improve cardiovascular fitness, methods like high-intensity interval training (HIIT), steady-state cardio, and progressive overload in resistance training remain the gold standard. For true altitude adaptations, living or training at genuine high altitude is the only proven method.
• Informed Decision Making: While they might add a novel challenge or aid in specific respiratory muscle training, users should be aware of the scientific limitations and not mistake them for a shortcut to the benefits of true hypoxic training. Prioritize proven training principles and consult with a qualified fitness professional or healthcare provider if you have concerns or specific training goals.