What are the effects of altitude training masks on human health?

From the Guidelines

Altitude training masks can have both positive and negative effects on human health, but the current evidence is limited and inconclusive.

Effects of Altitude Training Masks

The effects of altitude training masks on human health are highly individualized and depend on various factors, including the hypoxic dose, environmental conditions, and individual predispositions 1.

• Positive effects: Altitude training can improve cardiovascular health, increase red blood cell production, and enhance athletic performance 1.
• Negative effects: Altitude training can also lead to acute mountain sickness (AMS), respiratory problems, and decreased oxygen delivery to the muscles 1.

Sex Differences in Responses to Hypoxia

Research suggests that there are sex differences in responses to hypoxia, with women potentially being more vulnerable to AMS and having different physiological reactions to hypoxia 1.

• Respiratory muscle training: Targeted training of the respiratory musculature may be beneficial for women preparing for altitude training 1.
• Hormonal influences: Sex hormones can influence hypoxia responses, and hormonal-cycle and/or menstrual-cycle phases may be factors in acclimatization to altitude and efficiency of altitude training 1.

Recommendations for Altitude Training

Based on the current evidence, recommendations for altitude training include:

• Adequate acclimatization: Gradual exposure to high altitude to allow the body to adapt 1.
• Slow ascent speed: Ascending to high altitude at a slow pace to reduce the risk of AMS 1.
• Preventive medication: Using medication such as acetazolamide to prevent AMS 1.
• Respiratory muscle training: Incorporating respiratory muscle training into altitude training programs, particularly for women 1.

From the Research

Effects of Altitude Training Masks on Human Health

• The use of altitude training masks has been studied in various research papers, with some investigating their effects on endurance performance and others examining their impact on cardiorespiratory fitness and pulmonary function 2, 3, 4, 5, 6.
• One study found that simulated altitude training, which can be achieved through the use of masks, can increase maximal oxygen uptake and improve inspiratory fitness 4.
• However, another study found that training masks such as the Elevation Training Mask (ETM) may not lead to greater overall improvements in VO2max and pulmonary function compared to high-intensity interval training (HIIT) without the mask 4.
• The effects of altitude training are mediated primarily by acclimatization, rather than by hypoxic exercise, and living high-training low has been shown to improve sea level performance 5.
• A study on the effects of a respiratory training mask on steady-state oxygen consumption at rest and during exercise found that the mask did not affect metabolic, ventilation, and oxygen saturation at rest, but blunted respiratory rate and minute ventilation during exercise 6.

Physiological Responses to Altitude Training Masks

• The use of altitude training masks can lead to decreased fractional expired O2 and increased fractional expired CO2, as well as decreased SpO2 and increased ratings of perceived exertion (RPE) during exercise 6.
• Altitude acclimatization can improve oxygen transport and utilization, but hypoxic exercise may not provide any additional benefits for well-trained athletes 5.
• The mechanism of improvement in sea level performance due to altitude training is primarily an increase in erythropoietin leading to increased red cell mass, VO2max, and running performance 5.

Potential Risks and Limitations

• Altitude training can lead to decreased training loads, reduced speeds, and reduced power output, which may not be beneficial for well-trained athletes 5.
• High altitudes can lead to appetite suppression, inhibition of protein synthesis, muscle wasting, excessive ventilatory work, and metabolic compensation that is not advantageous for competitive athletes 5.
• The use of altitude training masks may not be suitable for all individuals, particularly those with certain medical conditions or those who are not accustomed to high-intensity exercise 6.