High Altitude Training
Living or training at high altitude (or simulated altitude) to stimulate red blood cell production, improve oxygen-carrying capacity, and enhance endurance performance
Bottom Line
High altitude training is one of the most well-researched performance enhancement strategies in endurance sports. The science is robust: reduced oxygen at altitude triggers EPO release, increasing red blood cell mass and oxygen-carrying capacity.
The key insight:
- "Live High, Train Low" (LHTL) is the gold standard
- Sleep at altitude (real or simulated) for adaptations
- Train at lower altitude to maintain workout intensity
- 2-4 weeks minimum exposure needed
Evidence status:
- Decades of research on elite athletes
- Meta-analyses confirm 1-4% performance improvements
- Individual response varies significantly (responders vs non-responders)
- Used by virtually all elite endurance programs
A proven intervention for serious endurance athletes. The main barriers are access (living near mountains or affording simulation equipment) and the time commitment required. Not worth it for recreational athletes unless you have easy altitude access.
Science
How Altitude Works:
The Hypoxic Response:
- At altitude, air pressure drops → less oxygen per breath
- Body detects low oxygen via kidneys (HIF pathway)
- Kidneys release erythropoietin (EPO)
- EPO signals bone marrow to produce more red blood cells
- More red blood cells = higher oxygen-carrying capacity
Key Adaptations:
- Hematological: Increased red blood cell mass, hemoglobin, hematocrit
- Ventilatory: Improved breathing efficiency, higher ventilatory response
- Muscular: Enhanced mitochondrial function, capillary density
- Metabolic: Improved fat oxidation, glycogen sparing
Altitude Thresholds:
| Altitude | Effects |
|---|---|
| 0-1,500m | Minimal physiological stress |
| 1,500-2,500m | Moderate hypoxia, EPO response begins |
| 2,500-3,500m | Optimal for LHTL protocols |
| >3,500m | Significant performance impairment, risk of altitude sickness |
Timeline of Adaptations:
- Hours: Increased ventilation, heart rate
- Days 1-3: EPO peaks (2-3x baseline)
- Week 1-2: Red blood cell production increases
- Week 2-4: Measurable hemoglobin mass increase
- Week 3-6: Performance benefits manifest
Research Highlights:
- Levine & Stray-Gundersen (1997): Landmark LHTL study showing 3% improvement in 5K time
- Chapman et al. (1998): Identified responders vs non-responders based on EPO response
- Bonetti & Hopkins (2009): Meta-analysis found 1-4% performance improvement
Supporting Studies
8 peer-reviewed studies
View all studies & compare research →Practical Protocol
Live High, Train Low (LHTL) - Gold Standard:
| Parameter | Recommendation |
|---|---|
| Living altitude | 2,000-2,500m (6,500-8,200 ft) |
| Training altitude | <1,250m (4,100 ft) |
| Hours at altitude | 12-16 hours/day minimum |
| Duration | 3-4 weeks minimum |
| Timing | 2-3 weeks before competition |
Natural Altitude Camps:
- Popular locations: Boulder/Flagstaff (USA), Font Romeu (France), Iten (Kenya), St. Moritz (Switzerland)
- Live at altitude, drive down to train
- Most practical for professional athletes
Altitude Tent Protocol:
- Set up tent in bedroom
- Start at equivalent of 2,000m, progress to 2,500-3,000m
- Sleep 8-10 hours per night in tent
- First week: adaptation (expect some sleep disruption)
- Weeks 2-4: full protocol
- Train normally during day
Altitude Mask Training (Different Mechanism):
- Does NOT simulate altitude (no low oxygen)
- Creates breathing resistance (inspiratory muscle training)
- May have some benefits, but not through EPO pathway
- See Inspiratory Muscle Training instead
Intermittent Hypoxic Training (IHT):
- Short exposures (1-2 hours) to hypoxia
- Less effective than LHTL
- May help with acclimatization before altitude travel
Camp Timing:
- Return from altitude 2-3 weeks before goal race
- Benefits peak 14-21 days post-altitude
- Some athletes compete directly from altitude
Training Adjustments at Altitude:
- Reduce intensity first 3-5 days
- Expect 5-15% performance decrease
- Increase hydration (higher fluid losses)
- Allow more recovery between sessions
Risks & Side Effects
Acute Mountain Sickness (AMS):
- Headache, nausea, fatigue, dizziness
- Usually occurs above 2,500m
- Most people acclimatize within 1-3 days
- Descend if symptoms worsen
Sleep Disruption:
- Very common first 1-2 weeks
- Periodic breathing patterns
- May affect recovery initially
- Usually resolves with acclimatization
Overtraining Risk:
- Altitude is a stressor
- Combined with hard training can lead to overreaching
- Monitor HRV and subjective fatigue
- Reduce training load initially
Altitude Tent Considerations:
- CO2 buildup if tent not properly ventilated
- Some find enclosed sleeping claustrophobic
- Need to monitor oxygen levels
- Partner may not want to sleep in tent
Contraindications:
- Severe anemia (get iron checked first)
- Uncontrolled hypertension
- Severe lung disease
- History of altitude sickness
- Pregnancy
Iron Requirements:
- Red blood cell production requires iron
- Many athletes become iron depleted at altitude
- Check ferritin before altitude camp
- Supplement if ferritin <50 ng/mL
Who It's For
Ideal Candidates:
- Competitive endurance athletes (runners, cyclists, triathletes, swimmers)
- Already training at high volume (10+ hours/week)
- Have specific performance goals
- Live near mountains OR can afford simulation equipment
- Have 3-4+ weeks to commit to protocol
Good Fit:
- Athletes preparing for major competition
- Those seeking marginal gains at elite level
- Professionals with access to altitude camps
- Serious amateurs with budget for altitude tent
Not Worth It For:
- Recreational athletes (better to focus on training fundamentals)
- Those with limited time (<3 weeks)
- Beginners (other interventions will give bigger gains)
- Anyone with altitude-related health concerns
Responder Considerations:
- ~50% of athletes are "responders" with strong EPO response
- ~25% are "non-responders" with minimal benefit
- ~25% have variable responses
- Only way to know is to try (or genetic testing)
How to Track Results
What to Measure:
Blood Markers (Pre/Post Camp):
- Hemoglobin (expect 1-2 g/dL increase)
- Hematocrit (expect 2-4% increase)
- Ferritin (ensure adequate iron)
- Reticulocyte count (shows red cell production)
Performance Metrics:
- VO2max testing (expect 2-5% improvement)
- Time trial performances
- Lactate threshold pace
- Power at threshold
Daily Monitoring:
- SpO2 (pulse oximeter) - expect 88-94% at 2,500m
- Resting heart rate
- HRV trends
- Sleep quality
- Subjective energy/fatigue
Tools:
- Pulse oximeter - essential for tent users
- Oura Ring or WHOOP for HRV/sleep
- Training log for performance tracking
- Blood tests before and after camp
Expected Timeline:
- Week 1: Performance decrease, adaptation symptoms
- Week 2-3: Stabilization, beginning of adaptations
- Week 4+: Performance improvements emerge
- Post-altitude: Benefits peak 2-3 weeks after return
Top Products
Altitude Tent Systems:
- Hypoxico ($5,000-8,000) - Industry leader, used by Olympic programs
- Altitude Tech ($3,000-5,000) - Good mid-range option
- Higher Peak ($2,500-4,000) - Budget-friendly
Components:
- Hypoxic generator (creates low-oxygen air)
- Tent enclosure (fits over bed)
- Pulse oximeter (monitor SpO2)
- Oxygen analyzer (verify tent levels)
Monitoring Equipment:
- Pulse Oximeter ($20-50) - Essential for safety
- Altitude watch - Tracks elevation if training in mountains
Altitude Masks (Different Purpose):
- Training Mask, Elevation Mask, etc.
- Do NOT simulate altitude (no hypoxia)
- Provide inspiratory muscle training instead
- Much cheaper ($30-80) but different mechanism
Cost Breakdown
Natural Altitude (Living in Mountains):
- Free if you already live there
- Travel/accommodation costs for camps vary widely
- Professional camps: $2,000-5,000+ for 3-4 weeks
Altitude Tents:
| System | Price Range |
|---|---|
| Basic altitude generator | $2,000-3,000 |
| Tent enclosure | $500-1,000 |
| Complete system | $3,000-5,000 |
| Premium systems (Hypoxico) | $5,000-8,000 |
Rental Options:
- Many companies rent altitude systems
- $500-1,500/month typical
- Good for trying before buying
Ongoing Costs:
- Electricity for generator
- Replacement filters
- Oxygen analyzer calibration
Cost-Benefit Analysis:
- Professional athletes: Usually worth it (sponsor funded)
- Serious amateurs: Rental for key training blocks
- Most athletes: Focus on other interventions first
Podcasts
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Discussed in Podcasts
28 curated moments from top health podcasts. Click any timestamp to play.
Altitude as a metaphor for business growth challenges
Hormozi compares scaling a business to climbing to high altitude where the air gets thinner. He notes that entrepreneurs at every revenue level experience the same feeling of overwhelm because growth always stretches your capacity.
"the air only gets thinner, the higher you go. And so if you're constantly reaching for growth, you will always be out of breath."
Building lung capacity through skill development
Using the altitude analogy, Hormozi explains that as you develop skills, tasks that once felt impossible become easy, like returning to low altitude after training high. Your baseline competence rises over time.
"But now you have the lung capacity to breathe thinner air. And so when you go back down to baseline, the air is thick. You can run for miles and you don't get tired."
Singular focus is the key to breathing at altitude
When overwhelmed, cut everything that does not directly generate revenue. The most successful operators at the highest levels share one trait: singular focus on one thing rather than spreading attention across many projects.
"And that is what allows you to climb the mountain and be able to breathe and not suffocate because it gets thinner and harder the higher up you go."
How oxygen deprivation triggers altitude adaptations
Cambridge researcher Andrew Murray explains that oxygen is critical for ATP production. At altitude, the body compensates by breathing harder and increasing red blood cells, though thicker blood becomes harder to push through capillaries.
"Oxygen is absolutely critical for almost every process in the body. Just about every tissue uses oxygen to make energy in the form of ATP, the universal energy currency of the cell. And if oxygen levels fall, the amount of ATP that can be produced and the amount of energy available to the cell is reduced."
Blood oxygen maintained up to 7,000 meters through red blood cell increase
Research samples taken up to 8,400 meters showed that blood oxygen content is maintained up to about 7,000 meters because increased red blood cell count compensates for each cell carrying less oxygen. Urine becomes alkaline as kidneys excrete bicarbonate to counteract respiratory alkalosis.
"We took samples as high as 8,400 metres, and interestingly enough, we found that even up to about 7,000 metres, the blood oxygen content was maintained, by which I mean you had more red blood cells, each of them was carrying less oxygen, but the fact that there was more of them meant that the total amount of oxygen in your blood was the same."
Real-world altitude monitoring on Everest Base Camp trek
Laura Soule monitored her physiology trekking to Everest Base Camp at 5,300 meters. Blood oxygen dropped to 90% of normal after an 800-meter altitude gain in one day, heart rate increased 10-20 BPM at rest, and urine pH spiked with each altitude jump before normalizing.
"Now that sounds like that was an enormous change in altitude in one day, 794 metres. Yes, it really was a big jump up that day. It was quite hard work and you really saw it in the experiments that we were doing. My blood oxygen level had dropped down to about 90% of what it normally is, which is quite a big difference."
Three types of altitude sickness and their symptoms
Deputy coroner Wendy Kipple explains the three types of altitude sickness: acute mountain sickness (headaches, nausea), HACE or high altitude cerebral edema (brain swelling, hallucinations), and HAPE or high altitude pulmonary edema (fluid in lungs). Rapid descent is the treatment for all three.
"there's actually several different types of altitude sickness. There's acute, let me get to my, I've got acute mountain sickness."
HAPE causes dry land drowning with white froth
High altitude pulmonary edema (HAPE) is the most common cause of altitude-related death. It presents with rapid breathing, exhaustion, constant coughing, and gurgling from the chest. Victims show white froth from the nose and mouth, essentially drowning from edema buildup in their lungs.
"if somebody dies from it, a lot of times I will see kind of a white froth coming from their nose and mouth, which is kind of like a drowning. But it's dry land drowning, basically. They're drowning from the edema that's building up in their lungs."
Four-year-old dies within two hours at 9,800 feet
A child with corrected arterial stenosis was cleared to fly by his cardiologist but died within two hours of arriving at 9,800 feet in Breckenridge. The cardiologist did not understand the difference between a pressurized airplane cabin and actual high altitude exposure.
"I was like, well, there's a difference between flying in a pressurized cabin of an airplane and driving up to 9,800 feet. Yeah. And where your atmospheric pressure is much less. Because it's not the lack of oxygen. It's the lack of atmospheric pressure that helps us take in that oxygen."
Gladys Ingalls performs mid-air wheel replacement at 2,000 feet
In 1926, pilot Art Goebel lost a wheel mid-flight. Wing-walker Gladys Ingalls strapped a replacement wheel to her back, transferred between planes at 2,000 feet, scooted down to the chassis, and attached the new wheel without a parachute.
"Gladys straps a plane wheel to her back and they head up. This story is wild, but the situation, is it everything that it seems? As Andy Zhang mentions in his TikTok, Gladys had done this before."
Wing-walking and archery performed without parachutes
Gladys Ingalls performed blindfolded wing-walking and mid-air archery on biplanes over Los Angeles. Until 1927, there was no law requiring aerial stunt performers to wear parachutes.
"She proved her worth when she walked blindfolded on the wings of a Curtis JN4 biplane as it flew over Los Angeles. And also, she mastered mid-air archery."
Simulated hypoxia for cycling at elevation
The podcast introduces a discussion on simulated hypoxia devices and tents that are becoming popular at gyms for athletes preparing for high-altitude events like the Leadville 100 mountain bike race.
"We're also going to talk a little bit about simulated hypoxia. It's getting more and more popular at gyms or through different devices that you can get. And if it's worth implementing, especially for athletes doing Leadville, like the question that we got from Ian here asking about that."
Who to Follow
Researchers:
- Benjamin Levine, MD - Pioneer of LHTL research at UT Southwestern
- Robert Chapman, PhD - Leading altitude physiology researcher
- Randall Wilber, PhD - USOC altitude expert
Practitioners:
- Elite endurance coaches worldwide use altitude camps
- Kenyan and Ethiopian runners train at natural altitude
- Many Olympic programs have altitude facilities
Athletes:
- Eliud Kipchoge - Trains in Iten, Kenya (2,400m)
- Mo Farah - Used altitude camps extensively
- Most elite marathoners and distance runners
Synergies & Conflicts
Essential Combinations:
- Iron supplementation - Required for red blood cell production
- Adequate sleep - Recovery crucial during adaptation
- Proper hydration - Fluid losses increased at altitude
Pairs Well With:
- Zone 2 Cardio - Base building at altitude
- HRV Training - Monitor adaptation and recovery
- Sleep Environment - Optimize tent sleeping
- Electrolytes - Replace increased losses
Timing Considerations:
- Avoid starting new hard training blocks at altitude
- First week should be reduced intensity
- Peak hard training in weeks 2-4
- Plan return timing carefully (2-3 weeks before race)
What to Avoid:
- Don't combine with other major stressors (caloric restriction, new supplements)
- Avoid altitude masks during altitude tent use (different mechanisms)
- Don't compete immediately upon arriving at altitude
What People Say
Professional Use:
Research Consensus:
Common Experiences:
Criticisms: