How Altitude Training in Kenya Improves Marathon Performance

When the world talks about marathon greatness, one place almost always comes up: Kenya. From the highlands of Iten to the dirt roads that cut across the Rift Valley, Kenya has become synonymous with endurance excellence. Year after year, Kenyan runners dominate international marathons, leaving athletes and coaches asking the same question: What’s their secret?

While there are many different factors at play, including those related to body structure, culture, an active childhood, a superior scouting system, and having many role models, one powerful element stands out — altitude training. For marathoners chasing their personal best, training at altitude, especially in places like Kenya, can be a game-changer. There is a reason why not just Kenyans, but 90% of all elite distance runners spend a significant time at high altitude.

In this blog, we’ll explore in detail how altitude training benefits runners, why marathon training in Kenya is unique, and how the physiological changes, including improvements in VO2 max, translate into better performance on race day.

What is Altitude Training?

Altitude training is a method where athletes train at elevations higher than 1,800 meters (about 6,000 feet) above sea level. Kenya’s renowned running hub, Iten, sits at about 2,400 meters (7,900 feet).

Although many runners believe that there is less oxygen in the air at high altitude, that is not the case. The amount of oxygen is similar to sea level, but the air pressure is lower, making it harder for our lungs to absorb the oxygen. In other words: altitude is a form of stress for our body, because it’s so much harder to absorb the oxygen from the air. And since we need oxygen for everything we do, our body quickly finds ways to deal with this, by making our whole cardiovascular system stronger and more efficient.

Initially, running at high altitude feels like a disadvantage — shortness of breath, faster fatigue, and slower paces. But here’s the science-backed magic: over time, the body adapts by producing more red blood cells and increasing haemoglobin levels. This allows the blood to carry oxygen more efficiently once the athlete returns to lower altitudes. So being at altitude is a good form of stress: it makes us stronger.

This is why the motto of most elite distance runners is: train high, compete low.

The Physiological Benefits of Altitude Training

By training in thin air, where it’s hard to absorb the oxygen, our body finds other genius ways to improve the oxygen delivery to the muscles. It transforms our body in measurable ways:

1. Increased Red Blood Cell + Hb mass : At high altitude, your kidneys release more erythropoietin (EPO), a hormone that stimulates red blood cell production. More red blood cells mean more oxygen transported to working muscles during a race, like a marathon. In addition to that, also more haemoglobin is produced. In other words, there are more ‘trucks’ available that can carry and deliver the oxygen to the working muscles

2. Increased production of capillaries : Capillaries are the tiny blood vessels that surround our muscles. They are like the roads that our blood uses to deliver the oxygen to the right place. When we train at high altitude, we get more of those capillaries.

   
   

   So apart from there being more trucks on the roads, our body also produces more roads. Imagine your muscles like a country full of towns with houses and roads. Some roads are highways; others are tiny village roads. Oxygen has to be delivered to the houses. If you have only a couple of highways, it’s hard to deliver the oxygen to all the right places. Some houses will be far away from the main roads. Having more of the tiny capillaries (the smaller village roads) helps to make the oxygen delivery more efficient.

3. More enzyme production : The way we produce energy when we run, is that our body uses carbohydrates and fats, and combines that with oxygen, to create ATPs (our bodies form of energy). During this process, our body needs certain enzymes. They can accelerate the entire process a million times. We have already seen how the oxygen delivery system of our body gets more efficient at altitude. We also create more of those necessary enzymes at high altitude. So that is another way of improving the production of energy, needed for running.

   
   

4. Improved VO2 Max : VO2 max — your body’s maximum capacity to take in and use oxygen — is a strong predictor of endurance performance. Studies show that athletes who train in high-altitude environments, such as Kenya, often see significant improvements in their VO2 max after returning to sea level. This, of course, is a direct effect of the previous physiological changes. More red blood cells, more Hb, and more capillaries all mean the oxygen delivery to our muscles has improved. And thus we will get an improved VO2max.

   
   

5. Enhanced Lactate Threshold : Training at high altitude does not just improve your VO2max. It also improves your lactate threshold – which is the maximum speed you can run where your body still clears as much lactate as it produces. Roughly this is comparable with your performance in a one-hour race. An improved lactate threshold will benefit everyone who runs distances between 3000m and the marathon. Maybe even longer – it’s not for nothing that ultra-running legend Aleksandr Sorokin often trains in Kenya.

   
   

6. Stronger Respiratory Muscles : Every breath at altitude requires more effort. Over time, this strengthens the diaphragm and respiratory muscles, improving breathing efficiency during hard runs. When returning to sea level, breathing costs less energy, so more energy is available for the muscles.

   
   

7. Mental Toughness : The physical adaptations are important, but equally vital is the mental resilience gained. Running in Kenya is never easy. Whereas some well-trained runners can feel like doing a 45 min easy run at home is as hard as brushing their teeth (they come home without breaking a sweat), running on the rolling red-dirt roads in the thin air of Iten is always a struggle. Easy runs feel like a moderate effort. Moderate runs feel pretty hard. And workouts feel like the hardest thing you have ever done in your life. It toughens you! When going back to sea level, suddenly racing feels pretty comfortable.

   
   

Why Kenya? The Altitude Advantage

There are many high-altitude training locations across the globe — from Colorado to Sankt Moritz, and from Flagstaff to Ethiopia. But Kenya has something special:

• Optimal Elevation: At 2,000–2,500 meters, Kenyan highlands sit at the sweet spot for altitude training. Research from Robert Chapman – who is one of the world’s leading scientists into high altitude training – shows that if you train at elevations of below 1900m, there is no significant improvement in VO2max or in performance. If you train too high (above 2,500 meters), there are still improvements in VO2max, but not in performance. One of the reasons for the latter could be that at that height, oxygen delivery becomes such a problem that sleep and recovery suffer.

  
  

• Training Environment: Kenya, and Iten in particular, has an entire network of undulating dirt roads and hilly trails. Those roads may be a little tough to run on when you are not used to it, but they really help to improve your running form and efficiency. Running on undulating trails also makes your muscles and tendons stronger than just running on flat tarmac roads. They stimulate our body in the best possible way. And for those who want to focus on speed or just concentrate on a certain workout, Iten also has a couple of tarmac roads available, including the famous 30km long Moi Ben road. Sure, these roads are not pancake flat, but Iten and Eldoret have tracks available where you can do your speed sessions.

  
  

• Running Culture: Training alongside elite distance runners who live and breathe marathon running provides unmatched motivation. It’s common in Iten to see world-class champions doing their easy runs on the same roads as beginners. Eliud Kipchoge, arguably the greatest marathon runner of all time, trains on the same track as young upcoming runners. In fact, many of our Kenya Camp guests have watched Kipchoge train, after which they did their own workout on the same track. Or go to Moi Ben road on a Saturday morning, to do your longrun or tempo, and you will share the road with World Major marathon winners, world record holders and Olympic champions.

  
  

• Community Support: Local communities respect and admire runners. In Iten, the entire atmosphere is built around endurance running, fuelling athletes with motivation and inspiration. Many of our Kenya Camp guests acknowledge this: training in Iten is like becoming part of a running community, where everyone is equal.

  
  

Training Structure: How to Build Up Your Altitude Camp

Altitude training isn’t about hammering every run. In fact, one common mistake runners make when they first arrive in Kenya is trying to push too hard too soon. Beware of this, because it can spoil your running camp.

Here’s what the typical training structure for a one-month marathon camp looks like:

1. Acclimatization Phase (Day 1-7)Focus on easy runs and light workouts. Your body needs time to adapt to the thin air. Run in zone 1-3, and avoid zone 4-5. The only ‘workout’ you can do in zone 5 are strides, or short hill sprints (8 x 10 sec all out uphill, with a 2 minute rest)

2. Base Building (Day 8 - 14)Increase mileage gradually with long runs on rolling terrain, and add sessions in zone 3-4 to improve your lactate threshold and remain efficient at marathon speed. You can do something in zone 5 (10K race pace), but keep it short. During the second week is when most runners feel like they are getting well adjusted.

3. Quality Sessions (Day 14 - 30)Add interval training, fartlek sessions, and tempo runs. Kenyan fartlek training is legendary for its unstructured yet brutally effective “speed play.”

4. Peak Training (Final week)Your body is well adapted now, so you can mimic sessions that you do at home. In terms of mileage you may be able to run even more than at sea level, due to the ideal climate and abundance of rest, recovery and healthy food. Workouts close to race-pace are possible.

5. Return to Sea LevelAfter 3–6 weeks, heading back to lower altitudes allows athletes to reap the oxygen advantage. Performance benefits can usually be seen within the first 2-3 days after returning, as well as 14 – 28 days post-altitude training.

   
   

   

Common Challenges of Altitude Training in Kenya

It’s not all glory runs with elites. Training in Kenya comes with challenges:

• Oxygen Deficit: The first week is tough. Fatigue sets in faster, and recovery takes longer. You need to be careful in this phase. Be patient and have the confidence that things will be okay.

• Dehydration: The dry climate and warm weather at altitude leads to increased fluid loss. Make sure you drink enough. At Kenya Camp we offer water bottles of 10-20 litres to our guests and most of them drink lots of them!

• Sleep Disturbances: Some athletes find it harder to sleep during the initial adjustment period. This is quite normal, and a result of the body not yet being able to absorb enough oxygen.

• Pacing Discipline: Trying your best to run the same pace in your easy runs at altitude as you do at sea level, is a mistake. Runners must learn to slow down and listen to their bodies. Leave your pride at home, and run at the right effort, even if that means you run at a pace that you feel like is way beneath your level.

• Altitude paradox: This is something most runners are not aware of. At high altitude, our maximum heart rate and our threshold heart rate are lower than at sea level. Also our maximum lactate values are lower. Scientists call this the altitude paradox: on the one hand most runners have a higher heart rate and higher lactate levels when they do an easy run at altitude (compared with sea level), but then when they try to go all out, they don’t just run slower, but their actual heart rate and lactate levels also don’t reach as high. More about this in another blog. For now, the point is: you may need to adjust your zones a bit. If your marathon heart rate or zone 3 at home is around 170, this is likely to be around 165 in Kenya. A difference of 5 beats is pretty common. Take that into account and control yourself to get the biggest benefits.

  
  

Overcoming these challenges, however, builds the grit marathoners need. And it gives you the right training stimulus as well.

Kenyan legends like Eliud Kipchoge, David Rudisha, and Brigid Kosgei have all trained their whole life in high-altitude environments. Their dominance on the world stage isn’t coincidence.

But it’s not just Kenyan-born athletes who benefit. Many international marathoners — from Mo Farah, and Paula Radcliffe, to Sifan Hassan, Emile Cairess and Aleksandr Sorokin — have spent significant time training in Kenya to harness the same altitude advantages.

The takeaway? Whether you’re a recreational marathoner or chasing an Olympic dream, marathon training in Kenya levels the playing field by offering the same environmental edge.

Practical Tips for Runners Considering Altitude Training

1. Plan for 3–6 Weeks: A two-week camp can still help you to improve, but 3 – 6 weeks are more effective in terms of performance. Many of our Kenya Camp guests have come for two weeks, after which they smashed their personal bests at home. But if you have the time available, extent your stay and come a little longer. At Kenya Camp we have this option.

2. Ease Into Workouts: Don’t chase paces during the first week. Let your body adjust.

3. Prioritize Recovery: Sleep, nutrition, and hydration matter more at altitude.

4. Stay Humble: Training with elites can be inspiring but resist the urge to match their pace.

5. Time Your Return: Schedule your altitude block so you return to sea level either a few days, or 2–3 weeks before your race.

Altitude training in Kenya isn’t just about running in thinner air — it’s about transforming how your body uses oxygen, building mental resilience, and immersing yourself in a culture that lives and breathes endurance. The altitude training benefits are clear: higher red blood cell count, improved VO2 max, improved lactate threshold, and a mindset forged in challenging conditions.

Whether you’re an elite chasing a podium or an everyday runner aiming for a marathon PR, training in Kenya’s highlands could be the boost you’ve been searching for.

So lace up, embrace the red dirt roads, and remember — the secret isn’t just in Kenya’s air; it’s in how it teaches you to endure, adapt, and rise stronger.