Altitude Camps: Live High, Train High,
or Just Spend High?
This is part of our series on the science and technology shaping elite athlete performance in 2026. As ever, this is not a manual written from the touchline. It is a map of where the evidence is strong, where it is thin, and what a performance department should weigh before committing to a camp.
Few training methods carry the mystique of altitude. The image is powerful: athletes living and training on a mountain, their blood quietly adapting, returning to sea level transformed. Around that image sits a substantial industry of dedicated camps, hypoxic tents, altitude-simulation chambers, and a set of claims that range from well-evidenced to wishful. This article separates the two. Altitude training has a genuine physiological basis and a real, if variable, effect. It also has a large individual-response problem and a commercial layer that often promises more certainty than the science delivers.
Why altitude works, in principle
The core mechanism is well established. At altitude, the air holds less oxygen, and the body responds to this reduced availability by producing more erythropoietin, the hormone that stimulates the production of red blood cells. Over weeks of exposure, this can increase total hemoglobin mass, the amount of oxygen-carrying protein circulating in the blood, which in turn can improve the delivery of oxygen to working muscles. For endurance athletes, whose performance is closely tied to oxygen transport, this is a meaningful adaptation.
The classic strategy built on this is “live high, train low” (LHTL), developed by Levine and Stray-Gundersen: athletes sleep at moderate altitude to trigger the blood adaptation but train at lower altitude to avoid the drop in training intensity that hypoxia forces. The logic is elegant: capture the adaptation without paying the training-quality penalty. As we will see, though, the evidence for whether that elegance actually beats the older approach of simply living and training high is more contested than the theory suggests.
What the evidence actually shows
The physiological effect is real but should be stated precisely. A foundational study found that elite endurance athletes living at 2,500 m for 24 days while training lower significantly increased both hemoglobin mass and red cell volume, changes accompanied by improved maximal oxygen uptake and faster 5,000 m times (Wehrlin et al., 2006). That is a clean demonstration that the mechanism can produce a performance-relevant result in elite athletes.
A 2025 systematic review and meta-analysis of thirteen studies added important nuance, and it is nuance that cuts against the marketing. Compared with low-altitude training, the review found significant improvements in hemoglobin concentration and in time-trial performance, no meaningful effect on maximal oxygen uptake, and a hemoglobin-mass result that was directionally positive but less straightforward than the headline claim suggests (Deng et al., 2025). The review also flagged that its own conclusions are limited by the number and quality of the available studies. This is worth stating plainly, because hemoglobin mass and VO2max are precisely the numbers altitude vendors quote: in the most recent pooled analysis the VO2max benefit did not appear at all, and the hemoglobin-mass signal was weaker and less clean than the marketing headline implies.
Two things follow. The blood adaptation is real and reasonably well supported at the level of an individual foundational study. But when pooled across the recent controlled literature, the effect on the marquee metrics is smaller and less certain than the marketing implies, and the honest headline is closer to a probable, modest, variable benefit than a guaranteed transformation.
The orthodoxy the recent evidence complicates
There is a further finding in that meta-analysis that deserves its own paragraph, because it unsettles a widely held belief. The subgroup analysis found that the older “live high, train high” approach, and interventions lasting longer than three weeks, were the most effective for aerobic capacity (Deng et al., 2025). That complicates the tidy story in which “live high, train low” is the refined, superior successor to a cruder method, rather than overturning it: other network analyses still rank LHTL combined with low-altitude training highly for VO2max.
The truthful position is not that LHTH is superior, but that the hierarchy is not settled and appears sensitive to the outcome measured, the dose, the population and the protocol. LHTL has a strong theoretical rationale and real supporting evidence, but the claim that it reliably outperforms simply living and training at altitude does not hold up as cleanly as its popularity suggests. A department should hold the choice of model as genuinely open, dependent on the athlete, the logistics and the training goals, rather than defaulting to LHTL because it is the fashionable answer.
The individual-response problem
The most important practical finding in the altitude literature is that athletes do not respond uniformly, and the variability is large enough to undermine any one-size-fits-all approach.
Research on the variability of hemoglobin-mass response, drawing on 82 altitude camps across 59 elite athletes, found that hemoglobin mass increased in only 56% of camps overall, rising to around 65% when only camps above 2,000 m were considered (Nummela et al., 2020). Even more striking, among athletes who attended multiple camps, some always responded positively, some always negatively, and the majority showed both positive and negative responses across different camps. In other words, the same athlete can respond well to one camp and poorly to the next, so “responder” is not even a stable trait a department can rely on.
This matters enormously. It means altitude is not a reliable intervention that can be prescribed identically to a whole squad. It is a variable intervention whose effect depends on the individual, the altitude, the duration, the athlete’s iron status, and factors that are not fully understood. A camp that works for one athlete may do nothing for the teammate in the next room, and may work for that same athlete this year and not next.
Iron status: the prerequisite, not the detail
One driver of that variability is controllable, and it is the one a department most often neglects. Because the intended adaptation is hematological, the cheapest way to waste an altitude camp is to send an iron-depleted athlete to one. Erythropoiesis draws on iron, and the responder research repeatedly implicates iron availability in who adapts and who does not; the foundational Wehrlin study itself recorded a fall in ferritin alongside the rise in erythropoietic markers, a reminder that a camp actively depletes the substrate it depends on (Wehrlin et al., 2006; Nummela et al., 2020). The practical consequence is that iron status is a prerequisite, not a detail: assess ferritin and related markers well before camp, correct deficiencies early, and keep monitoring during and after exposure. Without that, a poor response may reflect a solvable substrate problem rather than a failed altitude strategy.
The dose question
The evidence also points to a threshold problem: too little altitude does too little. A narrative review synthesising the live-high-train-low literature into a common “hypoxic dose” found that the doses actually used in these interventions cluster in a range that implies meaningful adaptation requires substantial, sustained exposure, often more than many real-world camps deliver (Bonato et al., 2023). Camps at natural altitudes below 2,000 m remain popular for logistical reasons, but the hematological benefit at those altitudes is less reliable, which is consistent with the responder data improving sharply above the 2,000 m line.
The general guidance that emerges is that altitudes in roughly the 2,000 to 2,500 m range, sustained for more than three weeks, give the best chance of a meaningful blood adaptation. Shorter or lower camps may still have value for acclimatization or training-environment reasons, but they should not be sold, or bought, as reliable hematological interventions.
Real mountain versus simulated altitude
The commercial layer’s biggest promise is convenience: simulated altitude that delivers the adaptation without the travel. But simulated altitude is not one thing. Sleeping tents, hypoxic rooms and intermittent hypoxic sessions deliver very different exposure durations, and therefore very different doses, toward different goals. The physiological principle is the same, reduced oxygen availability triggers the same hormonal response, but the practical question is not whether the air is natural or simulated. It is whether the athlete accumulates enough hypoxic exposure to trigger the adaptation being claimed. Because athletes typically spend fewer hours per day in a tent than they would living on a mountain, the accumulated hypoxic dose is often lower, and the adaptation correspondingly smaller. Simulated altitude is a legitimate tool, but it is not automatically equivalent to a genuine camp, and the dose question applies to it even more sharply.
The position a department can hold
Altitude training is neither a myth nor a guaranteed edge. It is a physiologically real intervention with a genuine blood-adaptation mechanism, a meaningful but variable effect, and a serious individual-response problem that the marketing tends to skip.
The position the evidence supports is this. Treat the blood adaptation as real in principle but modest and uncertain in the pooled data, and be skeptical of headline hemoglobin-mass and VO2max claims, which the most recent meta-analysis found non-significant or negligible. Do not assume “live high, train low” is automatically superior to living and training high; the recent evidence does not support that hierarchy. Respect the dose: aim for roughly 2,000 to 2,500 m sustained for more than three weeks if the goal is a hematological benefit, and do not expect low or short camps to deliver it reliably. Above all, treat altitude as an individual intervention, not a squad-wide prescription: monitor hemoglobin-mass response where possible, expect that a substantial minority of athletes will not respond, and accept that the same athlete may respond differently to different camps. Plan the return window as deliberately as the camp itself, because if the goal is sea-level performance, a camp is a calendar decision as much as a dose decision, and the timing of competition after return has to be planned rather than assumed. And weigh the considerable cost of a camp against that uncertainty, and against the next-best use of the same budget.
Altitude can genuinely help the right athlete under the right conditions. The error is treating it as a reliable transformation for everyone, when the evidence describes a variable adaptation that has to be earned, monitored, and, often, accepted as absent.
How this series is made, and how to read it: this is editorial analysis, not a practitioner’s memoir and not a systematic review. PERFORM’s pieces are researched and drafted with the assistance of AI tools, then reviewed, edited and fact-checked by our editorial team against primary sources, peer-reviewed literature, clearly labelled preprints, industry reports, league and company announcements, and practitioners’ own published work. Where the evidence is strong we say so; where it is limited we treat it as limited; where a claim comes from a vendor or corporate announcement we treat it as a hypothesis, not proof. The views here are our editorial position, drawn from the published record rather than first-hand experience inside an elite performance department. Where practitioners are named or quoted, those words are their own. Where we couldn’t verify a claim, we left it out. And where you have the hands-on experience we’re writing about, we’d rather hear from you than pretend to it.
References
Bonato, G., Goodman, S. P. J., & Lathlean, T. J. H. (2023). Physiological and performance effects of live high train low altitude training for elite endurance athletes: A narrative review. Current Research in Physiology, 6, 100113. https://doi.org/10.1016/j.crphys.2023.100113
Deng, L., Liu, Y., Chen, B., Hou, J., Liu, A., & Yuan, X. (2025). Impact of altitude training on athletes’ aerobic capacity: A systematic review and meta-analysis. Life, 15(2), 305. https://doi.org/10.3390/life15020305
Nummela, A., Eronen, T., Koponen, A., Tikkanen, H., & Peltonen, J. E. (2020). Variability in hemoglobin mass response to altitude training camps. Scandinavian Journal of Medicine & Science in Sports, 31(1), 44–51. https://doi.org/10.1111/sms.13804
Wehrlin, J. P., Zuest, P., Hallén, J., & Marti, B. (2006). Live high-train low for 24 days increases hemoglobin mass and red cell volume in elite endurance athletes. Journal of Applied Physiology, 100(6), 1938–1945. https://doi.org/10.1152/japplphysiol.01284.2005