Do altitude training masks really work? What the science says

Maryke Louw
36 minutes ago
9 min read

Altitude training masks promise “mountain-level” performance gains without leaving sea level – but do they actually work? This evidence-based guide breaks down what research reveals about altitude masks: their effects on endurance, strength, and respiratory fitness; how they compare to real altitude training; and what safety issues to consider before you strap one on.

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A track and field athlete wearing an altitude mask.

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In this article:

How is actual high-altitude training (without a mask) beneficial?
What is an altitude training mask?
Is using a high-altitude training mask beneficial?
How to use a high-altitude training mask
Side effects and safety
How we can help

How is actual high-altitude training (without a mask) beneficial?

High-altitude environments have less oxygen per mouthful of air that you breathe. When training at altitude, the reduced oxygen intake (known as hypoxia) triggers increased production of red blood cells and other changes, such as improved breathing efficiency.

These adaptations improve the blood’s oxygen-carrying capacity and enhance oxygen delivery to muscles. Altitude exposure can therefore boost an endurance athlete’s aerobic performance once they return to sea level.

What is an altitude training mask?

An altitude training mask is a device worn over the mouth and nose during exercise. It typically uses adjustable airflow valves to restrict breathing, creating an effect similar to being at altitude. By limiting air intake, these masks make your body work harder for each breath.

The idea is that this “simulated altitude” will induce the same adaptations as real high-altitude training.

An athlete running while wearing an altitude training mask.

For amateur runners who can’t easily do stints in the mountains, altitude masks are an appealing and affordable alternative. They are far cheaper and more accessible than traveling to a high-altitude training camp. In fact, masks are often marketed as a way to get “comparable effects” to altitude training without the expense.

🤷‍♀️ But do they live up to these claims? Let’s examine what the science says for two key areas: endurance and strength performance.

Is using a high-altitude training mask beneficial?

Endurance

Wearing an altitude mask does seem to simulate some aspects of altitude, but the research results on the benefits for endurance are mixed and somewhat tentative.

Positive results

On the positive side, training with the mask does create a hypoxic (low-oxygen) and hypercapnic (high-CO₂) breathing environment for the athlete.

This lower oxygen level can spur some of the same muscular and respiratory adaptations as altitude, such as improved breathing efficiency and oxygen utilization in muscles. A recent review of a body of research noted that “most studies report an acute hypoxic effect and improvements in cardiorespiratory parameters”.

In practical terms, research has found slight improvements in VO₂max (maximum aerobic capacity) or in ventilatory thresholds (the points at which breathing becomes more laboured) in those who trained with masks. For example, one study on runners and cyclists reported that the mask-wearing group improved their aerobic and anaerobic thresholds significantly more than the control group who trained without masks.

This suggests the mask can enhance certain endurance-related fitness markers like how efficiently you use oxygen at high effort.

Additionally, there is research that found that altitude masks act as a respiratory muscle trainer – the added breathing resistance strengthens the diaphragm and other breathing muscles over time.

Stronger respiratory muscles can delay fatigue during long stints of exercise, which is beneficial for endurance.

Results that indicate no benefit

That said, not all evidence is rosy.

Several other studies that compared masked training to normal training found that both groups improved, and that there were no significant differences between the groups’ improvements.

For example, in a study where a group of military cadets in the USA had to wear high-altitude masks during their PT sessions for six weeks, there was no significant improvement in their fatigue index, anaerobic capacity, peak power, VO₂max, or time to exhaustion compared to those who didn’t wear the masks.

So, what’s going on?

Looking at the body of research out there, it seems that altitude masks do not replicate all the benefits of real altitude.

There is robust evidence that training with an altitude mask fails to improve your blood composition. They make it harder to breathe but do not actually lower the oxygen percentage in the air – so they don’t stimulate increased red blood cell production like high-altitude living and training does.

A man running in the mountains. — Altitude training masks don’t replicate all the benefits of true altitude training – most notably, they don’t increase the number of red blood cells in the blood.

Instead, any performance gains from high-altitude masks are more attributable to improving the strength of your breathing system, leading to improved lung function and breathing economy. And there are indications that it also improves how well your muscles use oxygen.

💡 In summary, the endurance benefits from altitude masks are modest. Using the mask will make your workouts feel harder and can improve your breathing strength and possibly your aerobic threshold.

Strength

Altitude training masks are not beneficial for strength training – in fact, they might be counterproductive.

Unlike endurance athletes, strength athletes do not stand to gain from a hypoxic, high-CO₂ training state. When you lift weights or do high-intensity anaerobic exercise, your muscles rely on quick bursts of energy and maximal effort. If you’re wearing a mask that restricts your breathing, you’ll fatigue faster and be unable to lift as heavy or as explosively.

One systematic review of the science bluntly concluded that for strength workouts, using an altitude mask “could be detrimental”.

Altitude training masks can have a negative impact on strength training and sprinting.

Moreover, altitude masks do not improve anaerobic “lactic” performance like sprinting or high-power movements. The mask might train your respiratory muscles, but it doesn’t translate to generating more power in a 30-second all-out effort. Instead, it often reduces the power you can produce by making you winded sooner.

💡 In summary, if your goals include strength, power, or high-intensity anaerobic performance, an altitude mask is more hindrance than help.

How to use a high-altitude training mask

You should use a high-altitude training mask with caution. 👉 Please don’t skip the section on side effects and safety further down.

If you want to experiment with using a mask, it’s important to do so strategically – you can’t just wear it on every run and expect miracles. Let’s take a look at how these masks have been used in research studies that did show some benefits.

What types of training?

As mentioned above, altitude training masks do not improve pure anaerobic performance (e.g. sprints of up to 30 seconds and lifts).

However, it does make sense to use them during high-intensity interval training (HIIT) sessions – with typically 2 to 4 minutes per interval – or other hard sessions, such as cycling at submaximal speeds (e.g. 85%–95% VO₂max), where oxygen demand is high and respiratory training can make a difference.

The goal isn’t to improve anaerobic energy systems, but to increase aerobic capacity and breathing efficiency under duress.

💡 So, research protocols with these masks usually incorporate them into HIIT or other hard workouts, rather than easy sessions or long runs. For example, you might wear the mask for interval runs, hill sprints, or hard cycling sessions 2–3 times per week, over a period of 6–8 weeks.

Focus on maintaining good form under the breathing strain, rather than hitting a specific pace. As you adapt, you can tighten the mask valves (simulating higher altitude = less airflow) or add an extra interval.

Keep regular unmasked training sessions (hard and easy) in your plan so you can still train at full intensity and gauge your true fitness improvements.

In essence, use the mask sparingly but purposefully, just as you would other advanced training techniques.

How much airflow restriction?

Studies on amateur athletes have generally used masks set to simulate a moderate altitude (not maximum restriction) to allow them to complete the workouts.

A gradual progression is key: start with the lowest resistance setting until you get used to the sensation, then incrementally increase the “altitude” level over several sessions. Always allocate plenty of recovery between high-intensity masked workouts, as they could tax your system heavily.

Examples of altitude training masks on Amazon:

Side effects and safety

The good news is that studies report that healthy individuals can generally tolerate mask exercise without serious problems.

However, training with an altitude mask undoubtedly feels harder – and there are some important safety considerations.

By restricting airflow, the mask creates a state of hypoventilation (you breathe less air per minute) and can cause CO₂ retention (hypercapnia) in the body.

The elevated CO₂ levels from rebreathing can lead to a feeling of air hunger and even a bit of disorientation. In practical terms, you may experience symptoms like light-headedness, dizziness, shortness of breath, or a headache, especially when you first use the mask.

🚨 Pushing too hard with the mask can cause some people to hyperventilate or even faint, which is obviously risky. This is why it’s critical to never use the mask during dangerous activities (for example, cycling in traffic) and to train in a safe, controlled environment until you know how your body reacts.

Always listen to your body – if you start to feel tingling, extreme breathlessness, or woozy, remove the mask and recover.

People with cardiovascular or respiratory conditions – such as high blood pressure, asthma, chronic obstructive pulmonary disease, or heart disease – should seek medical advice before deciding whether to use a high-altitude mask.

And proceed with caution if you’ve ever had anxiety related to breathing or panic attacks; introducing a mask might trigger those sensations.

How we can help

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About the Author

Maryke Louw is a chartered physiotherapist with more than 20 years' experience and a Master’s Degree in Sports Injury Management. Follow her on LinkedIn and ResearchGate.

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Do altitude training masks really work? What the science says

How is actual high-altitude training (without a mask) beneficial?

What is an altitude training mask?