While I appreciate what Nick posted, I think it is worthwhile differentiating between being inspired by a stellar performance in an activity that we ourselves engage in passionately, and admiring a stellar performance in an activity that holds very little attraction for us personally. For me, Jennifer most certainly falls in the latter category, and all of the folks Nick mentioned fall in the former. Even within an activity, there are categories that may inspire or merely evoke admiration: trail hiking vs wild, off trail adventures; distance running on a track vs road racing vs cross country; Tour de France vs cyclo cross, etc.
For me, Jennifer most certainly falls in the latter category. Speaking as one who has run 50 miles, anyone who can run ~46 miles/day for 50 plus days on a trail as rough as the AT is reputed to be has my unstinting admiration and respect, even if it is something that has no appeal for me whatsoever. Ditto for the US 10K record holder. Track racing bores me silly, but running down in the mid 26 minute range is an awesome achievement. Let us celebrate all of those who excel in their activity and inspire others to do the same to the best of their abilities. It is hard, hard work, and they deserve our collective praise. My 2 cents.