A while back I was asked in an interview for a magazine about how to prepare for an event at a high altitude if the athlete is from a much lower location. Good question. I experience this myself every year when I make my annual summer pilgrimage from Scottsdale near Phoenix to Boulder, Colorado. That means an altitude gain from around 1850 feet (~680 meters) to 5500 feet (~1676 meters). It certainly makes a noticeable difference in training for a few weeks after arrival.
I learned this the hard way last week when I did a bike road race after only one week in Boulder. It started at about 5500 feet and climbed to around 8300 feet (~2529 meters) in just over 9 miles (14km). Needless to say, I wasn’t ready for the thin air. It was by far the greatest drubbing I’ve ever been on the receiving end of in a race. I could tell that my legs were doing fine, but there just didn’t seem to be enough O2. Now, just a week later, it’s apparent from another similar climbing workout today (to 8800ft – ~2669m) that there are positive changes taking place. But there is still a long way to go. I’ve written about this phenomenon before here and here.
As mentioned, I was asked if I would answer some questions to help the writer get a handle on preparing for an event in Colorado at altitudes very similar top those I experience every year in Boulder and in the mountains above the city. Here are my answers to his questions…
Q. Why is riding at altitude so difficult? Physiologically speaking, what happens to the body?
A. Oxygen delivery to the muscles is reduced at altitude. This means that the athlete’s aerobic capacity (VO2max) will decline as altitude increases. There are only three physical attributes that define endurance “fitness” and VO2max is one of them. The research suggests something like a decrease of about 2% for every 1000 feet (~300m) of altitude gain for someone who is not adapted. Many of the Colorado passes are above 10,000 feet (~3030m). So compared with sea level, the athlete’s VO2max could decrease about 20% by the top of one of these climbs. That’s huge!
Q. Is it possible to train for altitude?
A. It’s possible to prepare for altitude by living at altitude, not by training for altitude. The research suggests that you need about four weeks at roughly 6600-8200ft (~2000-2500m) to get a significant benefit. This could cut the losses of VO2max in half. (Note that some athletes in studies don't improve their aerobic performance at all by living at altitude.)
Q. Can you suggest a workout someone could do to improve their altitude preparation?
A. Training at altitude is probably not going to be of any value in adapting. It takes something on the order of around 12-16 hours a day of exposure to a sufficiently high altitude to beneficially adapt. More is better. A few hours working out at altitude would be of little or no value and might even be detrimental to performance as one would not be able to train at as great an intensity (power or pace) as at low altitude, so muscular fitness would decline.
Q. What about an exercise that can be done, not at altitude, that will prepare you for when you come out to high altitude. In other words, are there things that lowlanders or east and west coasters can do to prepare specifically for the altitude component?
A. Short of living at high altitude (or simulated high altitude) for four weeks, there is nothing physiologically the athlete can do to prepare for altitude—other than to get in the best aerobic condition possible. The higher the athlete’s VO2max is, the better his/her performance at high altitude.
Q. I recently interviewed pro cyclist Andy Schleck. He said something about how he was training at altitude, but three or four days before the race he was going down to sea level to really get the benefits. He couldn't explain why. His trainer had simply told him this. Is there anything to this?
A. At altitude there is a loss of muscular fitness since the workouts can’t be as intense as at sea level. Coming back down for a few days (perhaps as much as two weeks) allows this muscular fitness to be re-established by higher-intensity training. The aerobic benefits from the period at high altitude last perhaps four weeks, so the athlete should be ready to race well a couple of weeks after descending and rebuilding muscular fitness but before the aerobic gains of altitude are lost.
Q. Short of living and training at altitude, when is it ideal for someone who is coming from low levels to arrive at the high race site to get "acclimatized" for an event like this?
A. Acclimatization starts as soon as the person arrives at altitude. But the gains are quite small, negligible, for the first several days. Also, the old idea of arriving immediately before a race has been shown to not work. So athletes can arrive whenever they want in the days prior, but should fully expect not to go as fast in a race as they would at sea level. There is no magic bullet for altitude.
Note: If you’d like to learn more about altitude and endurance performance I’d recommend reading Altitude Training and Athletic Performance, by Randy Wilder, PhD. Dr. Wilber runs the human performance lab at the US Olympic Training Center in Colorado Springs, Colorado.