You're absolutely right: the basic outline is not a difficult problem. The "difficult problem" I was referring to is taking a sample population and drawing con

You're absolutely right: the basic outline is not a difficult problem. The "difficult problem" I was referring to is taking a sample population and drawing conclusions about how much sitting is OK, what kind of exercise is OK, and whether the above are casually related to factors we otherwise describe as "aging." For a substantial segment of the population, sitting all day, even with 30 minutes of intense exercise somewhere in the middle, probably does contribute to unfavorable health outcomes. For others, that might not be so. For many people, there may be underlying causes of both unhealthy habits and unfavorable health outcomes.