An article published in the Journal of Sports Medicine and Physical Fitness and discussed in a Washington Post blog suggests that students who are more physically fit get better grades.  The article is quick to point out the better grades are not necessarily causally linked with physical fitness.  Let's consider why they may not be causally linked but also consider the impact on cost-effectiveness analyses of physical fitness interventions if the causal link is real.

First, why may they not be causally linked? Among adults, it is quite possible that those who are more physically fit have more "self-determination" or "drive" or a greater sense of "self-efficacy" in general. If true, that could imply that those who are more likely to take the time to become physically fit or maintain their physical fitness are also more likely to succeed in other areas.  Among students it could mean that those whose parents encourage doing well in school also encourage doing well in other things and also take the time to monitor and manage their children's physical well-being very closely.  So, there are plenty of reasons that these two concepts may be correlated but the relationship may not be causal.

But suppose for a moment, that the relationship is causal. Suppose that being more physically fit makes a person better able to concentrate and maintain their concentration.  Suppose that being more physically fit enables a person to learn better if they are also more socially and mentally healthy as well as physically healthy.  There are lots of possibilities here.  What, then, would we need to do to fully appreciate the value of physical fitness programs?

First, we would need to make sure that to the degree that improved physical fitness enhances fitness in other domains of health, this is recognized and incorporated into the results. In other words, the health related quality of life impacts of physical fitness may go well beyond making someone just more vital or decreasing obesity or the eventual risk od diabetes and other complications of a lack of fitness.

Second, we would need to establish a link as to how much fitness improves grades (or learning more generally) and how that translates into a person being more productive and what the economic value of that productivity might be.  In fact, the productivity could also have an impact on physical and mental health later in life.  So, the relationship could actually be part of a favorable feedback loop that could have a large economic value throughout life.  Failing to capture this feedback loop in any long term predictions of the impact of a childhood fitness campaign could great understate the campaign's value.

Of course, we have plenty of money being spent on fitness for kids already.  Perhaps we do not need more.  But as we continue to consider how to use the limited public dollars for both health and education, we might want to consider how these two interact and efficiencies that can be gained from thinking about the two together.  Failing to do so may lead to inefficient resource allocation.  But doing so is certainly no simple matter.  And going so will require more data and a fairly sophisticated modeling exercise to incorporate all the possible effects of fitness on education and vice versa.