Why Train at Altitude?
April 18, 2025
Heading up to 5,000–10,000 feet to train? At altitude, oxygen molecules are more spread out (think beach balls at a giant empty beach vs packed together on a crowded one). Less oxygen per breath forces your body to adapt — learning how to deliver energy more efficiently with less air.
At first, it feels like running through quicksand. But give it time: the body becomes a lean, mean, oxygen-sipping machine. This adaptation is gold for endurance athletes, team sport players, and mountain adventurers alike.
The science:
- At higher altitudes, partial pressure of oxygen drops, making it harder for your lungs to pull oxygen into your blood.
- Your body compensates by working harder: breathing faster, pumping blood faster, and eventually building more red blood cells to deliver oxygen more efficiently.
Bottom line: Train high, and your body learns to get more out of every breath — a big advantage whether you're racing at sea level or scaling alpine trails.
How Altitude Affects Your Body
Training at altitude triggers two phases of change:
Immediate Effects (First 72 hours):
- 🔼 Fluid loss and dehydration (more urination + breathing out more moisture)
- 🔼 Headaches, poor sleep, mild inflammation
- 🔼 Reliance on glycogen (carbs) for energy
- 🔽 Appetite
- 🔼 Increased iron needs
Adaptations (After 2–3 weeks):
- 🔼 More red blood cells and hemoglobin
- 🔼 Better oxygen delivery to muscles
- 🔼 Formation of new blood vessels
- 🔼 Improved exercise tolerance (better lactate/pH regulation)
- 🔽 Resting heart rate
Why Oxygen Matters for Performance
VO₂ and VO₂ Max:
- VO₂ = volume of oxygen your body uses during exercise.
- VO₂ Max = maximum oxygen your body can deliver at peak effort.
At altitude, VO₂ max drops because your body simply can’t move as much oxygen. This means a workout that feels easy at sea level will feel harder at altitude — even if your pace or effort level stays the same. With proper acclimation, athletes can regain some of this lost VO₂ max — but it's highly individual.
What Is Considered "High Altitude"?
| Altitude | Meters | Feet | Impact |
|---|---|---|---|
| Near Sea Level | 0-500 m | 0-1640 ft | Minimal effects |
| Low Altitude | 500-2000 m | 1641–6562 ft | Minor aerobic impairment |
| Moderate Altitude | 2000–3000 m | 6562–9843 ft | Altitude sickness risk begins |
| High Altitude | 3000–5000 m | 9843–16,404 ft | Serious acclimatization needed |
| Extreme Altitude | >5500 m | >18,045 ft | Deterioration over time |
Pro tip:
Altitude sickness can happen even at “moderate” elevations. It's not just an Everest problem.
Essential Prep: Hydration, Iron, and Fueling
1. Hydration is King
- Start hydrating before you travel and continue throughout the day (not just during exercise).
- Add electrolytes to replace what’s lost from extra urination and breathing.
- Monitor urine color, weight, and bathroom breaks.
Hydration insight: Breathing harder at altitude = losing more water through your breath. It sneaks up fast.
2. Iron Matters More Than You Think
- Iron is critical for making hemoglobin — the protein that carries oxygen in your blood.
- Get a blood test 6–8 weeks before altitude training to check iron status.
- Boost intake of iron-rich foods (beef, eggs, lentils) or talk to a sports dietitian about supplementation if needed.
Low iron = poor red blood cell production = bigger struggle at altitude.
3. Fuel Up Right
- You’ll burn through carbs faster at altitude — bring extra snacks.
- Eat three balanced meals + 2–4 snacks daily.
- Focus on balanced meals with appropriate nutrients for your plans.
- Don’t skip meals, even if appetite tanks (liquid nutrition can help).
4. Sleep Strategy
- Sleep can get rocky at elevation.
- Pack a sleep aid toolkit: sound machine, favorite pillow, tart cherry juice.
- Prioritize recovery and avoid caffeine, alcohol, and heavy meals close to bedtime.
The Gold Standard: "Live High, Train Low"
The most effective altitude training strategy based on current research? Live high, train low.
- Sleep and live at higher altitudes to stimulate adaptation.
- Train at lower altitudes where you can push higher intensities.
You get the best of both worlds: altitude benefits without sacrificing training quality.
Travel Timeline for Race-Altitude Prep
Best case: Arrive at race elevation 14 days before competition.
- Rest for 1–2 days upon arrival.
- Allow 2 weeks for full acclimatization if possible.
- Some performance gains can start after just 5–7 days, but may take longer, variable based on individual.
If you can't arrive early:
- Accept that race day might feel harder.
- Adjust pacing expectations and prioritize hydration and fueling.
Altitude can supercharge your fitness — if you respect the process.Train smart, prep well, and you’ll turn the “thinner air” into a serious edge.
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