It is clear that there is a U-shaped association between sleep duration and mortality, with both short and long sleep linked with increased death rates.  This finding is underlined by two major recent research overviews - Gallicchio & Kalesan "Sleep duration and mortality: a systematic review and meta-analysis" and Cappuccio et al's "Sleep duration and all-cause mortality: a systematic review and meta-analysis of prospective studies".  There is so much interesting that one could write about this, but this particular blog post is triggered by a personal query that I have.  I try hard - and am mostly successful - to have a very healthy lifestyle.  I eat well, exercise well, keep a sensible weight, don't smoke, don't d