The Hypoxia Hurt Game
Your head hurts, you’re slightly nauseous, each step you take injects pain into every cell of your body, and you have a hard time wrangling the motivation to eat. Hungover? No. Just climbing at elevation. Welcome to the hypoxia hurt game.
As mountain athletes, the elevations that we play in affect our bodies and minds in many ways. If you’re like us, you want get the most out of your time trekking or climbing in the mountains, it’s important to understand the physiological changes that your body is enduring at elevation, and how they manifest for you.
How well you do at high altitudes depends on many variables to be sure. You can train for months in advance of your trip and be in the best shape of your life, but if you ignore the potential impacts of high altitude illness your hard work may all be for naught. Preparing for a high altitude trek or climb includes training, getting the essential equipment, some mental work, and understanding what your nutritional needs will be. But, the first and foremost way to prevent illness up high on your climb is knowledge.
How high is high?
Altitudes over 9,000 feet (2,743 M) are considered high. This means whether you are on Mount Baker, Kilimanjaro, or Aconcagua, you will be impacted no matter who you are and how well you do up high. As elevation increases, atmospheric pressure decreases. Lower pressure allows the oxygen molecules in air to spread out. This means that each of your inhalations at altitude contain fewer oxygen molecules. At the top of Everest (29,035 ft / 8848 M) the partial pressure of oxygen is one-third that of sea-level. If you were magically deposited at the top of Everest without prior acclimatization you would lose consciousness within minutes and you would die.
There soon becomes a lot of activity in your body as you arrive at higher altitudes. The first reaction is your body acclimates to lower pressure and less oxygen with both acute and longer-term changes. Initially, your body, wondering where all the oxygen has gone, responds by increasing your respiratory and heart rates to increase oxygen delivery to tissues. Then, your kidneys start producing bicarbonate and increasing urine production to keep your pH neutral. After a couple of days at a new elevation your heart and respiratory rates start to slow down as your pH returns closer to normal. Your body also responds by increasing a hormone called erythropoietin which in turn increases the production of oxygen-carrying red blood cells. Increased erythropoietin production starts within minutes of arriving at high altitude but takes 2 – 3 weeks to complete.
How to prevent illness
If you’ve ever rushed the acclimatization process, like a two-day ascent of Mount Rainier, or driven to the top of Pike’s Peak, you’re familiar with the headache that marks the onset of Acute Mountain Sickness (AMS). Other altitude-related illness such as High Altitude Pulmonary Edema (HAPE), High Altitude Cerebral Edema (HACE) and High-Altitude Flatulence Expulsions (HAFE) can also occur; the former two can be deadly, while the latter only threatens the welfare of your tent mate and lead you to end up sleeping outside. These risks can be minimized by following a proper acclimatization strategy, changing dietary habits, and in some cases by using medications.
If you are coming from lower elevations, or even sea level, those aren’t points against you in the game of high altitude mountaineering or trekking, it’s just something that needs to be strategically handled with each new elevation reached. You don’t need the centuries old genetic adaptations to altitude of a Sherpa or the Andean Quechua, just some basic things will go a long ways in helping you reach your goal.
As mountain athletes who endeavor to climb high and feel as strong as possible, the best way to work with the changes that altitude causes is to acclimatize. Practically, this means ascending to a new high point then returning the same day to sleep at a lower elevation. This climb high, sleep low approach allows your body to slowly adapt to the stress of performing in an oxygen deprived environment.
So, what’s a mountain athlete to do?
- If you’re joining a Mountain Madness trip, please read the section of high altitude illness in your departure info we send you; otherwise,
- Plan acclimatization into your schedule
- Reduce as much stress on your body as possible. Stay hydrated, rest, eat well
- Communicate how you’re feeling to your guide or teammates
- Listen to your body — there are times when you have to push through the hurt and others when it’s better to take a time out; it’s ok to take a break now and then
Some solid resources
Training by yourself or with a partner is fine, get a program dialed and stick to it. But, if you hire a trainer it’s worth considering finding someone that has some knowledge of high altitude climbing and trekking and what your body goes through. Alpine Athletics owner Lisa Thompson, who has climbed the Seven Summits and K2, has programs that train you, gives you advice on equipment and nutrition, and that provide invaluable insights from someone that has played the hurt game and overcame the challenges of high altitude.
Contributors: Dr. Tracee Metcalfe, Lisa Thompson/Alpine Athletics, and Mark Gunlogson