Altitude sickness kills climbers.
Altitude sickness is caused when your carbon dioxide (CO2) and oxygen (O2) levels get severely out of whack in the body.
While it can happen at any altitude, it is called altitude sickness because you are more prone to it at high altitudes because there is simply less oxygen in the air there than there is at lower altitudes (where most of us live).
At the top of Kilimanjaro, there is half the amount of oxygen than I am used to living in Seattle (which is essentially sea level).
There are lots of symptoms, but the net of it is that coming down with mild altitude sickness makes you feel pretty lousy, and severe altitude sickness can cause you to lose consciousness and die.
Altitude sickness is the #1 thing that turns back climbers on Kilimanjaro (and every other peak). The research varies as to how many climbers on Kili come down with altitude sickness (my guess is that the inconsistent data is because symptoms can be quite mild), but studies state that anywhere from 50% to 90% of all climbers on Kili do suffer its affects.
Two Methods to Reduce the Effects of Altitude Sickness
There are two known means to reduce the likelihood of developing altitude sickness:
- Ascend slowly to give the body time to adapt. My 7-day ascent was perfect for that (there is a direct correlation between the number of days on the ascent and the number of hikers that do not make the summit).
- The second is to take a drug, diamox. I also took the diamox.
I Believe There is a Third Method
Proper breathing technique.
A significant portion of the population doesn’t breathe as effectively as they could. I’ve talked about breathing habits before, but the super-short version is that everything from bad accidents to chronic levels of stress and anxiety to poor food choices create less-than-optimal breathing habits.
Those sub-optimal breathing habits result in a condition of low-grade chronic hyperventilation, and we start living our everyday lives in a CO2/O2 imbalance. So, now, if you connected the dots you’ll realize that if we are heading to climb with the levels already out of kilter, what is going to happen when we start climbing? You are taking something that is already out of balance and making it worse.
My Breath Training
Breathing mechanics. Most people that don’t breathe right (which used to include yours truly) and only use their upper chest for breathing.
Your lungs extend all the way down to about the bottom of the ribcage, and we should be using our entire chest to breathe. At rest it’s not a huge movement and you don’t move a lot of air, but you should still use it all. When you limit your breathing to your upper chest, it causes two problems.
- You end up using what are meant to be your secondary breathing muscles (those around your shoulders and upper chest) to do the majority of the heavy lifting. So, now muscles that were never designed to work that hard all the time are. Oops.
- Your body isn’t exchanging all of the gasses it needs to exchange on each breath, which leads to faster breathing, which perpetuates chronic hyperventilation. Chicken, meet egg.
Breath retraining is a ginormous topic in and of itself, and I’ll be saying a lot more about it in the coming months, but an easy way to start is to simply make sure you are using your entire chest for breathing.
- You can put one hand on your upper chest and one on your lower chest.
- The upper hand should largely stay fixed while breathing, while the lower hand should move.
Since we breathe 22,000 or so times a day, you can’t just take three practice breaths a day and expect to correct this in a few days. Work up to 40 breaths twice a day, and expect the process to potentially take months — or even years. It took me about 18 months of semi-regular practice to correct my breathing patterns. But, before that number discourages you, know that you will start seeing results A LOT faster, and you can use this drill any time you need to to calm yourself down or reduce anxiety.
Strength training. No, I’m not talking about getting huge biceps. I’m talking about strengthening the muscles you use to breathe. The primary muscle in breathing is this large muscle that lives in the lower half of your ribcage called the diaphragm. Rather than describe how it works, I’m just going to point you to this great video clip so you can see it in action. A really easy way to strengthen it is to take really slow breaths, about 2-4 seconds on the inhale and 6-10 on the exhale. Once again, we are talking 40 breaths, twice a day — same as above. There are other techniques and devices on the market that I’ll be talking more about in the future, but this is a great way to start.
Oxygen debt. I’m kinda cheating here, because talking about oxygen debt really isn’t about breathing. Instead, it’s about adapting to CO2/O2 imbalances. The body is hard-wired for survival, so it is always learning, adapting, and coping to what we put it through so it can be more efficient the next time we do that same activity (because the brain is all about being uber-efficient). So, one of the best ideas I could come up with for handing the CO2/O2 imbalance I was going to encounter on Kilimanjaro was to try to recreate that imbalance at sea level. The best way I had of doing that was by doing some really hard interval work. The idea was that the exercise would cause my body to burn more oxygen through hard exercise, thus releasing more CO2, and create short-term imbalances that my body could adapt to.
Personally, I feel that my breath training should probably get an enormous amount of the credit for how well I felt the entire trip and how fast I was able to make the trip to the summit and back on summit day.

