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ABIGAIL LARSON
Contributing Editor for the Master Skier
Abby has a master's degree in Exercise Science; she’s living in Bend OR and working as an exercise physiologist/nutritionist at Therapeutic Associates. She is a member of the Subaru Factory Team, recently made the World Cup Team and is trying to make the 2006 Olympic Team.
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Brooke Baughman skiing at altitude.
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Going from 500 feet to 6,500 feet can be a shock, as well as intimidating, for many skiers but just because the air is thinner doesn’t mean you can’t race like a winner!
All poems aside, the air really isn’t thinner; the barometric pressure is reduced. This decrease in barometric pressure decreases the pressure gradient between air outside the lungs verses inside the lungs; which reduces the amount of oxygen that is eventually forced into alveoli (where oxygen is absorbed into the blood stream).
Therefore less oxygen is available to bind to hemoglobin (red blood cells that carry oxygen to working muscles).
In the big picture this means more anaerobic work, which means more lactic acid; OUCH! So race velocity at altitude must be decreased from that normally used at sea level because of the tendency to produce more lactic acid at sub maximal velocities.
People who live at altitude can get around this phenomenon by producing more red blood cells (oxygen carriers), so what oxygen does penetrate the alveoli is utilized to the utmost extent.
This adaptation takes weeks to fully occur but 85% of the red blood cell gain occurs within the first 14 days at altitude. This is why many people go to “acclimatize” a week to ten days before the competition. Unfortunately this well-intended plan can backfire for many altitude novices.
Many athletes don’t take into consideration that acclimatizing to altitude is a considerable stress on the body. Even easy distance training must be ratcheted down a notch or two. It is easy to over-train during this adaptation period and by the time the competition is at hand the body is tired and stale. Sub maximal heart rate and cardiac output is increased making any given pace more difficult for the body.
Utilization of carbohydrate and fluids increases when acclimating to high altitudes due to the constant state of mild hyperventilation (increased rate of breathing).
Metabolism, while skiing, is shifted away from fat utilization in favor of carbohydrate due to the greater physiological demands while skiing at altitude. This increases respiration and fluid loss.
Additional fluid losses occur due to the low humidity and dry air found at altitude.
These are all excellent reasons to decrease exercise intensity and remember to hydrate throughout the acclimatization process.
None of this means that hard intensity workouts should not be performed; it just means that your easy skiing should be at a velocity that is less than what would be performed at sea-level.
Intervals should ideally be done three days before the first competitive event. It is necessary to learn what it feels like to go hard at altitude and what your limits are in order to avoid a big race-day “blow-up”.
Intervals that are about five minutes in length and begin at sub-race pace and finish at just above race pace are a good way to feel out your anaerobic boundaries.
Most people don’t have the luxury of arriving at a high altitude race venue with time to acclimatize. This usually isn’t as big of a problem as it might seem to be.
Most ski races are held at altitudes of 7,000 feet or less. At this altitude red blood cell saturation is still at 90% of what would be found at sea level (as opposed to 30% at the top of Mount Everest).
Exercise at these altitudes is safe, even for the unacclimatized, but shortness of breath and increased effort will be noticed.
Although no scientific evidence supports this, many athletes feel the worst after three or four days of training at altitude. This is probably due to carbohydrate depletion, dehydration and a slight over-training effect due to the excessive demands of exercise at altitude in the unacclimatized.
A good way to avoid this is to arrive one or two days before the competitive event, ski easy for a short period of time (if at all), drink a lot of water or carbohydrate-containing fluids and eat a diet high in carbohydrates.
If the race is over 15 km it is also important to drink carbohydrate-containing fluids at the rate of at least 16 ounces every hour.
Finally, don’t let a race at high altitude be an intimidating factor. Just be sure to race smart; start conservatively! There is no going back after blowing up at altitude. It is a lot harder to recover and clear lactic acid while racing at altitude verses sea level.
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