My happy place is the mountains. I dream of owning a mountain home and spending my summers backpacking, hiking, lake lounging and kayaking. This summer, I had a taste of mountain life. I spent a lot of time in the Sierras, which was interesting as I’ve also been following a rigorous 50-mile race training plan.
As you might imagine, running at 8,000 feet has been slightly more difficult than running at my usual sea level: my legs are heavy, my breathing rapid, and while warm, I feel more clammy than sweaty. Worried about how this was affecting my training, I fretted over the impact altitude running was having on my body. Was I still maximizing my workouts? Was dehydration taking its toll? Or, like the elites who spend time at length in places like Flagstaff or Park City, was I gaining a zillion new red blood cells?
Just what exactly is altitude training, and does it mean anything to amateurs like me?
How altitude affects our bodies
Air, regardless of elevation, is composed of 21% Oxygen and 79% Nitrogen. However, high altitude has a lower atmospheric pressure than lower elevations, which means there are fewer oxygen molecules per volume of air. Every breath we take at altitude delivers less oxygen than what our muscles need, resulting in rapid breathing as we attempt to take in more oxygen. The effects of hyperventilation can include dehydration, more alkaline blood (which causes it to hold onto the oxygen instead of drop it off to the muscles), and slowed digestion.
To adapt, the kidneys produce the EPO hormone (yes, that EPO), which triggers the creation of more red blood cells to aid in oxygen delivery to our muscles. Unfortunately for mountain weekenders like me, our bodies need more than just a couple days for this process. Within three to seven days at altitude we lose a significant volume of red blood cells, and while our bodies begin to make new ones immediately, it can take weeks to achieve an amount that will affect our running.
As anyone who has run in the mountains knows, it’s hard! Research shows that VO2 max (the maximum amount of oxygen you can take into your body during exercise) is lower at high elevations, dropping approximately 2% per 1,000 feet. Therefore, since I live at sea level, I can expect my VO2 max to be 12% less at 6,000 feet, the elevation of Lake Tahoe.
During a recent trip to the mountains, I attempted to do a speed workout, and while I had a solid workout, I ran significantly slower than I would have at home. This isn’t true for only amateurs like myself – when USATF events have been held in places of high elevation, they have published altitude adjustment calculators for expected results. A women’s 10K, for example, can be around 75 seconds slower at 5,000 feet elevation. In fact, much of the research on altitude’s effects on athletic performance came as a result of the 1968 Olympic games in Mexico City, an elevation of 7,349 feet. The majority of distance runners ran significantly slower than expected, with the exception of high-altitude trained East African runners, who were just beginning to emerge into the running scene.
How the elites train at altitude
Fifty years later, nearly all elite athletes use some form of altitude training. One of the most popular altitude training methods for elite runners is the “Live High, Train Low” method. This method allows athletes to reap the benefits of high altitude, but to train with the same intensity that they would at low elevations. This is why the use of altitude tents and locations like Flagstaff, Arizona and Mammoth Lakes, California are popular: their physical landscape allows runners to experience dramatic changes in altitude.
Deena Kastor, Meb Keflezighi and Ryan Hall have all lived and trained in Mammoth Lakes (Deena runs her own high altitude camp there), Greg McMillan’s distance training company, and other non-running athletic camps, are based out of Flagstaff, and Nike runner Emily Infeld just completed a 10-week stint at Nike’s altitude camp in Park City, Utah in preparation for the Olympics and spending some quality time with Shalane Flanagan and Amy Hastings.
How the rest of us can train at altitude
For recreational runners like myself, it is not feasible to move to one of these locations the months leading up to a goal race. So, how long do we need to spend at elevation to reap its benefits?
It can take several weeks to fully acclimatize, and while VO2 max will steadily improve, it won’t be what it is at sea level. This means weekend jaunts to the mountains aren’t going to cut it. Ideally, a person needs three to four weeks at elevation in order to acclimate and reap the benefits of increased red blood cell production, but the effects might only last 15 days or less after returning to sea level.
Therefore, careful timing is critical. When I returned from Lake Tahoe after one week, I took one day off to catch up on sleep, and then ran an 18-mile long run the next day. Surprisingly, those 18 miles felt easy! I was light on my feet, not sluggish at all, running a conversational pace at a respectable sub-9:00 minute pace. Had I scheduled my summer around a goal race and tapered appropriately, I believe I would have run a fantastic race.
Unfortunately, my goal race isn’t until October and the benefits of spending a few weeks at altitude will be long gone by then. As I write this post I am about to embark on an eight-day backpacking trip that will take me above 10,000 feet. I will have no opportunity to run. This is my last trip of the summer, before I head back to work and begin the fall grind of working and training. Much of the trip will be off-trail, will require map and compass navigation, and will have some extremely technical climbs and scrambles. The mental benefits of this trip will far outweigh the physiological benefits, and I’m okay with that. I’ll be in the most beautiful place on Earth, disconnected from my daily life, and challenging my mental endurance: perfect training for my first 50-miler!
Have you ever trained at altitude? What effects has it had on your training?