Many of us have heard the myth that air is “thinner” at higher altitudes, and that there is less oxygen available to our bodies at over 6,000 feet. While there is a drop in barometric pressure which makes drawing oxygen into our lungs and our bloodstream more difficult, the composition of the air remains at 29% oxygen, even atop Everest.
Altitude training describes the practice of training (running, specifically) for one to four weeks at an altitude of 6,000 to 10,000 feet when one normally trains at sea level. The reason that runners seek to expose themselves to this reduced air pressure is because low barometric pressure has been proven to increase the hormones that produce red blood cells and hemoglobin, as they need to adjust to an environment where extra oxygen is necessary. These effects last until a few weeks after they return home, meaning that the effort—not the distance, contrary to popular belief—that runners put into a given race will help them go further. In other words, your body works harder when you exercise at high altitudes, so exerting the same amount of effort at sea level (if that’s what you’re already used to) will be easier. Keep in mind that when you to train at an increased altitude, you may run three to fifteen percent slower than usual, but feel like you’re exerting the normal amount of effort. This is normal, and you shouldn’t gauge your progress by your time. In fact, ditch the stopwatch altogether and gauge your workout by effort instead, and decrease the target distance by 25%.
The timing of this is imperative. If you are planning on taking a training retreat in the mountains, plan to go for at least seven to ten days. This is because your body needs some time to acclimate. If you’re planning on running a race at a high altitude, you should either get there the recommended seven to ten days ahead of time, or otherwise do the race immediately upon arriving. This is because you either need to fully adapt to the lower barometric pressure and give your pulmonary system time to figure out what it needs to do to work at the new altitude, or to let your heart work at its normal rate without adapting. Anywhere in between (say you arrive only three days early) would make your system begin to adapt, but not fully become acclimated before the big day, meaning that your body may become stressed because it cannot adapt to the current conditions.
If you’re planning to train at a higher altitude, you may want to stock up on foods and supplements that are rich in iron, such as read meat and dark, leafy greens, to ensure that you have enough iron in your system to support the boosted hemoglobin levels that you are working to build. Adequate hydration is also very important, as it ensures that all available oxygen is being delivered to your cells.