For the past 11 months I've been working at a place that is at an elevation of 10 meters above sea level, while I've been living at an elevation of 306 meters for the past 7 or 8 years. I work 8 hour shifts 5 days a week and over this time I've been working there I've noticed a steady improvement in my health. At my previous job located closer to home I only lasted 2 months due to developing unbearable back pain. My current job isn't any easier on my back except that we stand on cushioned mats, but I doubt that would make such an extreme difference.
Throughout highschool I was at 131 meters and an hour further north than where I now live. The first few years after I moved to a higher altitude my health worsened and then seemed to balance.
College was 500 meters. While I lived on campus there my health noticeably worsened. It was also a few hours further north though.
http://veloroutes.org/elevation/"There is a significantly lower mortality rate for permanent residents at higher altitudes.[20] Similarly, there is a dose response relationship between increasing elevation and decreasing obesity prevalence in the United States.[21] This is not explained by migration alone.[22] On the other hand, people living at higher elevations also have a higher rate of suicide in the United States.[23]"
http://en.wikipedia.org/wiki/Effects_of_high_altitude_on_humans#Long-term_effects
