Trail Research Weekly #3 Alternatives To Altitude Training

The endurance sport world is obsessed with ways to increase exercise performance, and altitude training is possibly one of our favourite obsessions.

South African runners do altitude training in places like Dullstroom or the Berg, but most Capetonians and Durbanites don’t have the time or budget to go live and train at altitude for an extended block. There’s also a trade-off: because there’s less oxygen available, your training intensity usually has to come down. That matters, because oxygen sits at the centre of adaptation.

The good news? Sport scientists have been chasing the same question a lot of us have: can you get the performance boost of altitude training without actually going to altitude? Turns out, there are a few promising answers, and none of them requires quitting your job.

Quick Refresher: How Altitude Training Works

At altitude, there’s less oxygen pressure in the air. Your body responds by producing more erythropoietin (EPO), the hormone that tells your bone marrow to produce more red blood cells. More red blood cells = more oxygen-carrying capacity = a bigger aerobic engine = better performance when you come back down to sea level.

The Traditional Route: Live High, Train Low

Before diving into the alternatives, it’s worth being clear on what a traditional altitude block looks like. Runners get caught up in practices without fully understanding the specific protocols. The random training weekend in the Cederberg or Drakensberg has no benefit other than increasing training load, and it undersells how specific the protocol needs to be to elicit meaningful effects.

The established best-practice recommendation, drawn from decades of research on elite endurance athletes, is:

• Live at 2,000–2,500m for at least 12 hours a day.

• Stay there for a minimum of 3 weeks (dose-response research shows the erythropoietic benefit really starts to add up from around 500 hours of exposure).

• Do your high-intensity sessions lower down (ideally below 1,250m) so you’re not compromising your top-end training.

• Compete within 4 weeks after returning. Red blood cell mass decreases noticeably after that, so this is very much a use-it-or-lose-it adaptation.

This is the “live high, train low” (LHTL) model. It consistently shows up in meta-analyses as the more reliable approach compared to living and training entirely at altitude (LHTH), which tends to force athletes to train at reduced intensities for weeks on end and can leave them undertrained by the time they race. Elite athletes using LHTL protocols see average gains of around 4% in maximal aerobic power, a meaningful jump for anyone racing competitively.

Where South Africans Get This Right.

Johannesburg and surrounds sit at 1,700m+ elevation, which means Highveld-based runners get a low-grade, year-round altitude adaptation that others don’t. This is part of why so many strong SA distance runners have historically come out of Gauteng and the Free State (think Gerda Steyn and Zola Budd). For a dedicated camp within the 2,000–2,500m sweet spot, the classic options are towns like Dullstroom (2,076m) in Mpumalanga or Golden Gate Highlands National Park in the Free State. The catch for the “train low” half of the protocol is that these spots don’t always have easy access to low-elevation terrain for your hard sessions. That is something to plan for if you’re mapping out a camp, rather than just picking a high town.

If a 3-week relocation isn’t realistic for you right now, that’s exactly where the alternative methods below come in.

Heat Training: The Original “Poor Man’s Altitude”

This one’s been around the endurance world for a while, and it’s earned the nickname “the poor man’s altitude training” for good reason. Heat exposure triggers some of the same performance increases as altitude, minus the plane ticket.

A widely cited review by Baranauskas et al. (2021) comparing heat and altitude training head-to-head lays out the mechanism. When your core temperature rises during heat training, your body responds by shifting more fluid into the bloodstream, expanding plasma volume by anywhere from 4% to 15% within the first few sessions. That extra fluid means more blood returning to the heart, a bigger stroke volume, and a lower heart rate at any given effort. It’s a different pathway from altitude, which is mostly about adding red blood cells, but it can still move the needle.

The catch is that heat training needs to be done properly to work, and “properly” is more demanding than people assume. The recommended protocol is exercising for 90+ minutes a day in genuinely hot conditions (33-40°C, 30-60% humidity) for at least 10 days, with your core temperature around 38.5°C for most of the session. Shorter or half-hearted heat exposure hasn’t reliably shown the same benefits. Because training in the heat places considerable load on the body, overall training load will need to decrease.

And crucially, the review’s authors still lean toward altitude as the stronger stimulus for elite athletes prepping for cool-weather races. Heat training is a solid alternative, not necessarily a direct substitute.

Bottom line: if you’re already training for a hot race, or you have reliable access to heat exposure, this can be genuinely useful. Just remember that training load is still the biggest driver of adaptation, so passive heat may be the smarter option when you can’t afford to compromise key sessions.

Passive Heat (Hot Baths): Get the Benefits Without Affecting Your Training

A 2025 study by Jenkins et al. (2025) asked a controversial question: what if you skip the exercise-in-the-heat part entirely, and just soak in a hot bath?

Ten well-trained runners did five weeks of hot-water immersion: 45 minutes in a bath at 40°C+, five times a week on top of their normal training, which stayed completely unchanged. Compared to a control period, hot-water immersion produced the following adaptations:

• A 33-gram increase in haemoglobin mass
• A 284 mL increase in total blood volume
• A measurable increase in the heart’s left ventricle size (more room to fill with blood, meaning a bigger stroke volume)
• A 2.7 mL/kg/min bump in VO2max, and runners hitting exhaustion 0.8 km/h faster on the treadmill

For context, that haemoglobin mass increase is right in line with what you’d typically see from a traditional three-week “live high, train low” protocol. These adaptations seem to happen in two stages: first, plasma volume expands within the first week; then the kidneys respond to the resulting dilution by increasing red blood cell production. The result is more total blood volume, and eventually more red blood cells.

What makes this exciting for competitive runners is what didn’t change: training load, sleep quality, fatigue, soreness, and stress were identical between the bath and control periods.

There’s also a bonus use case here: regular heat exposure, even as little as three sessions a week, may help you hang onto the red blood cell boost from a traditional altitude camp for longer once you get home. That matters because those gains fades within 3-4 weeks of returning to sea level.

Bottom line: if you have access to a hot tub, bath, or sauna, this is probably the single best “no compromise” alternative on this list. It stacks on top of whatever you’re already doing rather than replacing it.

Sleep Tilted: The Weirdest One, But There’s Something Here

This last one is genuinely new and a little unusual, so treat it as an emerging finding rather than an established protocol, but it’s worth knowing about.

A study by Mazza et al. (2026) tested whether sleeping at a slight head-up tilt, about 6 degrees (blocks under the head-end of your bed) for five weeks could stimulate red blood cell production. The logic is that reducing central venous pressure during sleep, which happens when your head is elevated relative to your body, has previously been shown to trigger EPO release, the same mechanism as traditional altitude training.

Nine men slept tilted for five weeks and flat for five weeks, with a washout period between conditions. Researchers measured their blood markers after each block. The tilted-sleeping condition produced a small but statistically real increase in red blood cell volume and a corresponding rise in total haemoglobin mass, with no change in the flat-sleeping condition. Sleep quality and time spent in bed were identical between conditions, so unlike altitude tents, which are notorious for wrecking sleep, this didn’t seem to cost people anything on the recovery side.

To be clear about scale: the researchers themselves note this is a modest effect, and it comes from a small study (nine participants) that hasn’t been replicated yet. It’s not going to replace a real altitude block. But as a zero-cost, zero-side-effect addition, propping up the head of your bed for a few weeks before a big race, it’s an intriguing one for sure.

Bottom line: don’t build a training plan around this yet, but if you’ve got blocks lying around, there’s no downside to trying it.

Putting It Together

None of these three methods fully replaces a traditional LHTL altitude camp; the research is clear about that. Altitude still produces the most robust, well-established adaptations. But if a trip to elevation isn’t realistic before your next race, here’s a stack of alternative approaches proven to move the needle:

1. If you’re racing somewhere hot, do heat training, 90+ minutes in hot conditions, sustained for at least 10 days, as close to your race prep as makes sense, while reducing training load to accommodate the extra heat stress
2. Add passive heat exposure (hot baths, sauna) a few times a week regardless. It’s low-cost, doesn’t interfere with training, and the evidence for haemoglobin gains is now solid.
3. Prop up the head of your bed for a few weeks. Worst case, nothing happens. Best case, you’re getting a small haematological boost while you sleep.

More alternative methods are being used, and if there’s one thing you can rely on in endurance sport, it’s innovation. Max Jolliffe just won Badwater 135 after using a new heat-training suit for heat adaptations. Similar technology can be used for altitude-style exposure too, but as with all heat-training modalities, it comes with costs.

The mountain isn’t going anywhere, but if it’s not in the cards this training block, these are the closest things science currently offers, legally, to bottling it.

References

Baranauskas, M.N., Constantini, K., Paris, H.L., Wiggins, C.C., Schlader, Z.J. and Chapman, R.F. (2021) ‘Heat versus altitude training for endurance performance at sea level’, Exercise and Sport Sciences Reviews, 49(1), pp. 50–58. doi: 10.1249/JES.0000000000000238.

Jenkins, E.J., Killick, J.A., Zerilli, O., Douglas, A.J.M., Corr, L., Hughes, M.G., Tremblay, J.C. and Stembridge, M. (2025) ‘Long-term passive heat acclimation enhances maximal oxygen consumption via haematological and cardiac adaptation in endurance runners’, The Journal of Physiology. doi: 10.1113/JP289874.

Mazza, O.B., Gejl, K.D., Larsen, S. and Lundby, C. (2026) ‘Did you know: erythropoiesis is regulated by changes in posture’, Acta Physiologica, 242(6), article e70248. doi: 10.1111/apha.70248.

FAQs

What are the best alternatives to altitude training for runners?

The most evidence-supported alternatives to altitude training are heat training, passive heat acclimation through hot baths or sauna, and emerging methods such as head-up tilt sleeping. These methods may improve plasma volume, haemoglobin mass, VO2max, and cardiovascular efficiency.

Does heat training improve endurance performance like altitude training?

Heat training can improve endurance performance by increasing plasma volume, lowering cardiovascular strain, and improving thermoregulation. However, it does not fully replace altitude training because it produces a weaker hypoxic stimulus for red blood cell production.

Can hot baths or sauna increase VO2max in runners?

Passive heat acclimation from hot baths or sauna may increase VO2max by expanding blood volume and supporting cardiac and haematological adaptation. It is especially useful because it can be added after training without replacing key sessions.

Is live high, train low still the best altitude training method?

Yes. Live high, train low remains the most established altitude training method for endurance athletes. The protocol is most effective when athletes live at moderate altitude for several weeks while preserving high-intensity training at lower elevation.

How should runners choose between altitude training, heat training, and passive heat?

Runners should choose based on race conditions, training phase, and logistics. Altitude training is best when access and timing allow; heat training is most relevant for hot races; passive heat is a practical supplement when training load must be preserved.