You are correct - there are so many factors to consider, and I am by no means an expert and would definitely accept being wrong in any given area. The general advice that I can give, that will probably keep a person healthier than not, is to exercise, eat well, and not sit for too long. This goes beyond just DVTs - this is advice for living long in general. :) Even outside of clots, sitting is shown to severely cut back the benefits of exercise (although like all studies, this should be taken with a grain of salt as well). 66 percent of studies are wrong, as they say. The reverse advice goes as well - you should not stand all the time either - this is shown to have adverse effects as well.<p>And as a minor additional note - my 1-3 miles of walking tends more often towards the low end of that range (especially when I am in a rush to get work done), although I do randomly take longer walks (sometimes as far as 5 miles).