Altitude Problem

I just read an interesting article in "Inside Triathlon" by Matt Fitzgerald about the whole idea of the benefits (or lack thereof) of living and training at high altitude.  For a long time people have associated living at high altitude to providing an endurance benefit versus those who live and train at low altitude. Hence all the endurance pros living in Boulder, CO (5400 ft), and Mammoth Lakes, CA (7900 ft), among other places. Also, the US Olympic Training Center is in Colorado Springs, CO (~6200 ft). One can name other high altitude locales with close affiliations to the endurance community: Park City, UT (~7000 ft); Flagstaff, AZ (~6900 ft); Vail, CO (~8000 ft); Lake Tahoe, CA (~6200 ft); Santa Fe, NM (~7000 ft) to name a few. The list can go on and on. But do athletes who live in these towns perform better than those who live in San Diego, Boston, NYC, or Fargo, ND? Not necessarily. There are many, many factors involved in endurance sports, which is why it is so tough not only to be competitive in them but also to scientifically investigate them as well.

Altitude Basics
New insight into the altitude question arose a few years ago when exercise physiologists delved into its impact on fitness. The theoretical advantage of altitude lies in its ability to stimulate an increase in red blood cell mass in our bodies; in effect a natural, physiological blood doping. The relatively lower air pressure at higher altitude leads to lower transfer of oxygen into our bloodstream from our lungs. This leads to a relatively lower level of oxygen in our blood. Our body senses this lower oxygen level and is stimulated to produce more red blood cells in order to try to increase the amount of oxygen in the blood; more red blood cells means more oxygen carrying capacity, which in turn means a more efficient cardiovascular system. This process takes several weeks, though, so going to altitude for only a few hours at a time will do you no good. One needs to spend the majority of one's time at altitude (at least 16 hours per day) over at least 3-4 weeks in order to reap this benefit. This adaptation provides an increased ability to perform exercise at that altitude, and allows for a greater ability for endurance exercise at sea level as well.

The Altitude Problem
However, if you train at altitude, you are not able to push yourself to the extreme limit you would be able to at a lower elevation. Even though you have made some adaptations to account for the lower oxygen access, you still don't have the access to oxygen you would have at sea level. So for instance, if you do interval training at higher altitude you could only hit sub-maximal speeds compared to what you would hit at lower altitude. A result of this discovery was the "live high/train low" principle. By living at 6000 ft or above and training at 4000 ft or below, you can physiologically blood dope and still train to a maximal level. A study done by James Stray-Gunderson and Ben Levine found that those who lived high/trained low performed on average about 1.5% better than those who either lived high/trained high or lived low/trained low.

Tricks of the Trade
What does that mean for the pros? Some athletes are able to live in places where they can live and do most of their training at high altitude and but have relatively easy access to lower altitude for their more intense training sessions. Still others live and train low but sleep in low-oxygen tents to simulate the relative hypoxia of higher altitude. The only problem with this strategy is that if you're only sleeping in them for 8-10 hours per day, you may not be gaining any benefit from them. Recently some have been living and training at high altitude but will use supplemental oxygen for their intense sessions.

Plight of the Lowly Masses

What does that mean for the average weekend-warrior endurance athlete? Not much. It's rare that one can find oneself in an area where one can live at higher altitude and have easy access to a lower altitude. Plus, 1.5% does not account for much unless you are highly competitive/elite and shooting for an overall or age-group podium in competitive races such as sprint or olympic distance tris or half- or whole marathons. Longer distance races are tougher to show benefits since there are many more factors involved in performance over that duration. But, it does mean that going to high altitude for high intensity training sessions will be a waste of your time and energy, and may actually be detrimental, unless you simply want to see how your body responds to the higher altitude. If you already live at high altitude, you may have the advantage of being able to endure lower to moderate levels of exertion over longer races at lower altitudes but you may not necessarily be any faster.

So keep on keeping on wherever you are, any fitness is good fitness.