Altitude Training for Trail Runners: How It Boosts Performance

Altitude training isn’t just for elites escaping to European peaks anymore. As hypoxic tech becomes more accessible, trail runners are using altitude training to sharpen endurance, speed recovery, and handle tough terrain. David Byrne uncovers how it works, why it’s gaining traction, and why simulated altitude is no longer just for the pros. 

Altitude training has long been regarded as one of the best methods to naturally improve performance. 

For decades athletes across the globe have been heading to the hills in search of thin air as a means to get physiological adaptations that make competing down low easier. 

For a long time it was primarily elite cyclists, track and road runners who took advantage of this training method because the high costs of travel, and time away from work and family, meant only the pro’s really took advantage of it. 

But with the advent of altitude machines, it’s become easier for even weekend warriors or those less financially capable to add altitude training to their arsenal.

What Is Altitude Training?

Altitude training utilises the thinner air of heights, typically 2,000m or more above sea level, to force the body to adapt and become more efficient, doing so by increasing red blood cells and oxygen carrying capacity. 

Research suggests it leads to not only improved recovery, but a higher VO2 max and enhanced muscular endurance. Traditionally altitude training involved living or exercising in the mountains for weeks at a time, using one of three methods that will be explored later, but before looking at that, let’s delve into the science behind it.

How Altitude Training Improves Endurance and Performance

The higher the altitude, the lower the air pressure, which in turn means there are fewer oxygen molecules that you inhale with every breath. In order for there to be a noticeable change in oxygen density you generally need to go 1,800m or more above sea level, so in Australia that means you’re about 400m below the summit of Mt Kosciuszko. 

For the body to cope with the thinner air and carry the amount of oxygen it needs to operate optimally, it produces more red blood cells. Other adaptations include increased capillaries in muscles and improved muscle buffering, which is the body’s ability to clear metabolic byproducts. Some studies also suggest that muscle mass increases and metabolism speeds up, particularly after workouts. All of this means that once you return to sea level, recovery and performance both improve.

There are two ways to get high, or expose your body to thinner air. The first is naturally, by travelling to, and living or training in the mountains. This approach is challenging in Australia and New Zealand, largely due to the limited locations where you have the necessary altitude for the air to be thin enough. The second method is called simulated altitude training, which involves using equipment to create the low O2 environment. We’re talking altitude chambers, rooms or tents where space is filled with thin air, or wearing a mask attached to a machine. 

The downside of chambers or rooms is that normally you have to visit a gym or venue that offers such an opportunity, of which there aren’t a huge amount available, plus there’s the ongoing costs. 

Option two means having a machine at home so you can wear a mask or use a small tent at your leisure. Personally, I see this as the best alternative, but more on that later.

Three Types of Altitude Training

It’s important here to look at the most popular strategies used when at altitude, of which there are three: live high/train low, live high/train high and intermittent hypoxic training. The first of these involves spending most of your time living or sleeping in the high altitude environment, but travelling to a lower altitude for workouts. The key benefit of this is it allows you to passively get the gains of the thin air for extended periods, but then train better in a more oxygen rich environment. 

The live high/train high approach means spending all your time up high. The challenge here is your training intensity drops, but the stress on your body elevates. So you’re getting more exposure to the low O2 atmosphere, which theoretically increases the gains and speeds up the rate at which they occur. However, there is some conjecture as to whether the decrease in the quality of your training negates these benefits. 

The third method, intermittent hypoxic training, involves exposing athletes to short periods of high-altitude conditions, and usually requires using a specialised machine to simulate the low oxygen environment. For me, this is the best and most efficient of the three techniques, because you have more control over what you do, when you do it and how you approach your training. It’s also arguably cheaper.

Using Altitude Training Machines and Hypoxic Training at Home

Elite trail runner Simone Brick is one of those taking advantage of altitude training, and reveals how she first started.

“Back in 2018 while training for the World Mountain Champs in Andorra, because it was my first time travelling or racing at altitude, I was nervous about how it would go,” she explains. 

“So I borrowed a machine and I slept in a single-person hood tent five nights a week. I also ran in an altitude chamber two to three times a week. 

“Since then I have been using them any time I have a race at higher altitudes, so their role is intermittent and race dependant, but crucial for some of my higher races.”

Altitude machines or hypoxic generators work by taking in normal air, reducing the oxygen percentage, and then pumping it into either a mask you wear or a sealed space such as a room or tent. 

The user controls the simulated altitude they want to achieve by adjusting the settings. The quality machines look like commercial medical devices and can weigh 20kg or more. It’s also easy to adjust them to the altitude you want to simulate, with quality models capable of extreme and literally dizzying heights of up to 7,000m or more.

Normally when applying the live high/train low technique, you’re simulating altitudes from 2,500m to 3,600m and trying to maintain a blood oxygen level somewhere in the 85% to 90% range. 

But when ‘training high’ you’re looking at much higher altitudes, anywhere up to 5,000m or more, and exposing yourself for shorter periods. There’s a bit of detail as to how best to do this and I recommend speaking to an expert or someone experienced. You also should wear an SPO2 meter or pulse oximeter on your finger to keep an eye on your heart rate and oxygen saturation levels.

Simone has some good advice for the inexperienced. 

“Altitude training is great, but it’s also quite a large stressor on the body, so you can’t jump straight into doing heaps,” she says. 

“Start with small amounts of stimulus at lower altitudes and work your way up using pulse oximeters and fatigue levels as a guide to make sure you don’t overdo it. 

“For me any active work I do with the machines is on the bike at home, and normally I am pumping the altitude up quite high and go for a certain amount of time at an oxygen saturation percentage around 85%, starting with 20min and building that up over the weeks. 

“I also do passive high altitude breathing pulses, 5min on and 5min off, at much higher altitude for an hour while watching TV, plus sleep in the tent aiming for 90-92% oxygen saturations.”

Getting Results

So how long does it take to get results? Research suggests it varies on the individual and which technique they use. However, as a ballpark you can expect to start to see changes with a month of regular use. That said, the longer the period you sleep or train at altitude, the better the results and the longer they remain after returning to sea level.

Science has truly started to show the benefits of altitude training, and as trail runners seek to get more out of themselves and look for ways to gain a competitive edge, it only makes sense to explore ways of implementing it into your training regime. 

Just make sure that before getting stuck into it, you get professional advice about how to do so safely.