High-Altitude Running: Tips, Training, and Gear

High-altitude running is a great way to improve your performance. Increased aerobic demands make it harder to run at high elevation, but with adjustments to speed, hydration, and nutrition, altitude training for runners can boost your trail running possibilities. This article covers the benefits of altitude training and how best to prepare.

How much does elevation affect running?

A general threshold for what’s considered high-altitude running is 5,000 feet above sea level, where decreased oxygen pressure affects how you perform and feel in several ways.

• Breathing while running feels harder.
• Your heart has to pump more to deliver oxygen to muscles.
• Lactate accumulates faster, increasing fatigue and soreness.
• You lose more water through respiration, increasing dehydration risk.
• Mountainous, technical terrain requires trail running skills that differ from road running.

Your pace will naturally slow in response. A standard running-pace altitude conversion formula dictates that for every 1,000 feet of elevation, you’ll run 3% slower, meaning a runner with an 8-minute mile at sea level should expect closer to 8:45 at 5,000 feet.

Benefits of altitude training

As with any training method that introduces new challenges, such as running in the heat, in the rain, or in the snow, running at higher elevation triggers physiological adaptations that make it easier to return to baseline. Even a 3-4-week training block at 8,000 feet improves red blood cell production and aerobic capacity.

How to train for high-altitude running

Adjust your training before any mountain running event by updating intensity, pacing, and nutrition several weeks prior to arriving at elevation to help prevent altitude sickness symptoms.

How to acclimate to high-altitude running: timing

The standard acclimatization window is about 10–14 days. For mountain races of 6 hours or longer (like the Tor des Géants, which can last up to 6 days, or the Transalpine Run, a 7-day stage race), allow for a full 10-day acclimatization period. If possible, work out at a lower intensity the first 7-10 days, favoring a power walk over a hard tempo run.

How to train for high-altitude runs at sea level

At sea level, the exact conditions for high-altitude running are difficult to replicate. Tools like hypoxic tents and altitude masks can simulate decreased oxygen or provide respiratory resistance. Tempo intervals at 85–90% of your max heart rate with an oxygen mask are a viable way to train at sea level for high-altitude running.

Pace and recovery

Use a running-pace altitude conversion to recalibrate pace-based workouts, or focus instead on heart rate zones for a more reliable metric of effort. When training for climbs, use a 1:2 work-to-recovery interval ratio. Post-effort recovery also takes longer at elevation, so give yourself more than the standard 48 hours.

Nutrition

Caloric expenditure increases ~10–15% in high-altitude running due to higher respiratory demands and colder temperatures. Aim for 60–90 grams of carbs each hour during efforts over 90 minutes, and use your training period to test out diets designed for trail running.

Hydration

Drinking plenty of water while on the trails is vital in high-altitude running, as you lose twice as much fluid through respiration at 10,000 feet compared to sea level. Increase your fluid intake, monitoring hydration closely to avoid dehydration, and use trail running accessories like a flask or reservoir while on the move.

See how Rémi Bonnet combined diligent uphill training with trail running strength workouts, leading to a record-breaking performance.

Mountain running gear

Your trail running gear, clothing, and shoes make a huge difference in mountain running comfort and performance.

• The best mountain trail running shoes combine a 6-mm lug depth and full-length rock plate.
• The best mountain running gear includes a hydration vest, and trekking poles for ascents above 8,000 feet.

Don’t forget essential trail running clothing, such as a packable wind shell and comfortable socks.

Your high-altitude running questions answered

High-altitude running presents unique challenges that raise questions for potential participants.

Is VO2 max worse at altitude?

Yes, VO₂ max decreases at altitude because there’s less oxygen in the air, limiting maximal oxygen uptake regardless of fitness. Some rough estimates state that VO₂ max declines around 1–2% for every additional 1,000 feet above 5,000.

Why do elite athletes train at high altitude?

Training at high altitude 2-3 weeks prior to a competition allows elite athletes to capitalize on the benefits of altitude training after adapting to the higher elevation. This training takes place at specific camps in places like Flagstaff, Arizona (~7,000 feet elevation) and Boulder, Colorado (~5,430 feet).

How can I run better at altitude?

Improved high-altitude running performance is primarily a function of pacing discipline, hydration, and acclimatization. Aim to arrive 10–14 days before a target race, increase fluid intake, and recalibrate speed to manage trail running effort.

Challenge yourself and improve with high-altitude running

High-altitude running comes with high aerobic demand, increased fluid loss, and frequent technical terrain, making mountain running a true test of mental and physical toughness. By following these training tips for high-altitude hiking and running, along with smart adjustments to pace, nutrition, and hydration, running at higher elevation is an attainable goal for most runners and one that can prove beneficial when returning to sea level.