I have alway been susceptible to altitude sickness - even as a child (as has my mother) so it seems that I may have inherited it from her side. I've noticed over the years that while my state of physical fitness makes a difference in the distance that I can hike at altitude, it seems to make little difference as to the onset of altitude sickness. I can usually detect my symptoms at around 8000' and have at times been in great shape and gotten really sick and other times I have been in crappy shape and haven't been too badly affected. Acclimatization is the only thing that has helped me so far.

I have a funny story to relate about physical fitness and acclimatization. Years ago, I had gone on my annual 10+ day solo trip into the Sierra and since I was doing sections of the JMT, I felt so good at the end of the trip that I decided to do Mt. Whitney in a day the next week. I started early in the A.M. and was basically dancing up the switchbacks with no problem! Somewhere around Trail Crest, I passed an athletic looking couple who looked at me in amazement. I forget the mileage but they told me they ran an amazing amount of miles per week and thought they were in great shape (the altitude was kicking their butts) until they saw me skipping past. They regarded me with awe when they asked "What do you do to keep in such great shape"? my reply was "nothing" - which was essentially true since I really don't do exercise... That was my one shot at being looked at as a paragon of physical fitness!

Alan