Dr. Joan Vernikos has two books on Amazon.com: "Sitting Kills" and "Designed to Move". She also has her own web site and has many videos on YouTube. Vernikos was employed by NASA and had the job of watching over the health of astronauts in space. She found that the low or very low gravity in space aged the space men and women in much the same way people age on earth but the aging in low gravity was much faster.
Vernikos makes clear that "using" gravity, in the sense of resisting it, working against it, is important for our health. The basic idea I have gotten so far is Move! She and many other scientists and health workers have emphasized that all the hours of sitting at a desk, in a chair to watch tv, in a chair to read, in a chair to use phones and Ipads takes a toll on our health. Yes, the title of one of her books is "Sitting Kills". She recommends standing up, moving around, changing position, using the muscles of our bodies.
Having been warned by Vernikos, I try to move from in front of my computer every so often. Meanwhile, the add a new browser page feature in Firefox called Pocket has been getting better and better at recommending articles online for me to read. In the last few days, I read "Taking a stand for metabolic health" by Kathleen A. Page in the Univ. of Southern California Medical School.
http://stm.sciencemag.org/
I wasn't sure what was meant by "metabolic health" but it turns out the author means the metabolism of children who are overweight or obese. The article reports on having such children try both sitting for three hours and also interrupting the hours with 3 minutes of moderate walking every 30 minutes. Careful tests of appetite, food consumption and blood variables showed that the walking benefitted their bodies without increasing their voluntary food consumption.
I bought a three minute hourglass type timer and I have a 30 timer of the same design coming. I intend to use them alternately while computing and blogging.
