Have any visitors to Mexico City found the altitude to be a problem. If yes, how long did it take to acclimatise and what did you do and or take to alleviate the problem.
It's not really a "Problem." It is not the Himalayas. It is 2,200 meters high.
You will first discover that it is a little more difficult to walk fast in the airport while pulling your luggage as fast as you normally would. Just slow down a bit and you will be fine.
Within 2 to 3 days your body will have adjusted. The real fun is when you return home. You will find that can outrun all your friends for 2 days, run for an hour. without stopping.
Dynamisto is right on, I will add to drink more water, you tend to get dehydrated faster and I carry with me eyedrops. Otherwise you should not feel any discomfort.
Some people are more prone to altitude sickness than others, and age or general state of health has nothing to do with it. I am one of the lucky ones: however I must say that when I fly back into Mexico from sea level I usually have trouble sleeping for a couple of days.Edited: 07 April 2012, 16:12
Never had this problem at MC however Toluca at over 10,000' took about 24 hours to acclimatize.
Be careful the first couple of days with any alcohol consumption. One glass of wine here can have the same impact as 2 or 3 at sea level until your body adjusts. Otherwise, most people really do not suffer.
Whenever I arrive to Mexico City from a lower altitude, I get unusually tired from physical exertion for the first couple days (as the first poster mentioned, I first feel it in the airport, on the long walk to the metro station.) I sometimes have trouble sleeping as well, although I'm not certain it's because of the altitude. I would avoid scheduling anything strenuous (such as climbing the pyramids) for the first couple days.
More caution is warranted if you're ascending the mountains surrounding Mexico City. Mexico City is below the altitude where altitude sickness is generally considered to be a problem, but some locations on the mountains (including much of the highway to Puebla) are much higher. Theoretically, there's the potential for an unacclimated person flying into Mexico City and then immediately ascending the mountains to have trouble.
When I went to Mexico City, from Toronto, which is near sea level, I made sure to drink lots of fluids for a few days before going and tried to stay hydrated while there. I didn't feel anything unusual in Mexico City nor in Teotihuacán, where I climbed the pyramids less than 24 hours after landing in Mexico. (Trying to climb Volcán Malinche in Tlaxcala a week later was a different matter, haha!)Edited: 11 April 2012, 13:45
Anyone who gets altitude sickness in Mexico City should be seeing a cardiologist. What most are experiencing is breathing in the highly polluted air. Bring eye drops for that.