Nausea and high altitude running

Running & FitNews, Nov-Dec, 2002

I attempted the Pike's Peak Marathon last year but had to drop out due to severe nausea and vomiting. I'd love to try it again. Any thoughts?

Alan Mason

Hudson, NY

The symptoms of acute altitude sickness (AMS) include nausea, vomiting, headache, and severe fatigue. AMS can occur at altitudes of 2,500 to 3,000 meters, which is lower than Pike's Peak. Endurance athletes are no less likely to experience this than sedentary individuals. Some individuals are more prone to AMS because they do not adapt readily to high altitude.

Acclimatizing gradually (no more than an additional 300 meters per day above 3,000 meters) may help, as might several drugs, including acetazolamide and dexamethosone, but only under medical supervision.

Melvin Williams, Ph.D.

Norfolk, VA

In addition to altitude sickness, there are many factors that can contribute to nausea and vomiting while running and many runners suffer the consequences during marathons and ultra-marathons even where altitude is not an issue. High altitude can contribute to these problems.

* Dehydration--When you are running hard (up Pike's Peak at any speed is hard) it is often tough to drink enough fluids. This is compounded by any preexisting mild dehydration. If you had just traveled to the race, you may have been a little dry before it even started. The altitude also contributes to dehydration since the humidity is so low.

* Low glycogen stores--Sugar is the fuel that makes the body go. When this runs low, your body will use other sources, such as fat for energy, but it still needs glycogen to prime the pump. At a greater level of intensity, you will deplete your glycogen stores long before the usual 20-mile bonk.

* Altitude--Even if you are running at what would be an easy pace on a flat road at sea level, this may be an intense pace going uphill at altitude. At greater intensity, blood is shunted from the gastrointestinal tract. Absorption will be slowed and nausea can be intense.

* Level of exertion--It is not uncommon to experience nausea during and after an intense workout.

* Low sodium--This is more likely to be a problem in ultra-endurance events, but you do want to make sure that you replace electrolytes along with carbohydrates and water.

Cathy Fieseler, M.D.

Cleveland, OH

The most effective approach for a successful performance in the Pike's Peak marathon is to spend some time at a moderate altitude getting acclimated. Even a week or two at 7,000 feet, with some climbs to higher levels, would make the Pike's Peak effort much more enjoyable. Prepare as you would for any marathon, but with more hill work (up and down) and altitude acclimatization, if at all possible. Without it, Pike's Peak can be a nightmare.

Jack Daniels, Ph.D.

Cortland, NY