Spark! – Play, and pop-science

I’ll be honest.  I haven’t read John Ratey’s book “Spark.”  I’d like to, but I have a few others on the list ahead of it.  But I’m looking forward to it!

At the same time, I have to share my misgivings about the book.  Especially in light of my recent experiences with pop-science books about talent.

Dr. Ratey is a scientist.  But he’s not a medical doctor.  Or a movement scientist.  Or a physical educator.  He’s a psychiatrist.  That shouldn’t detract from his message, its importance, or its timeliness.  The book is no less important because of his qualifications.  However, I think it is slightly misguided.

I’ve read an article by Jacob Sattelmair (a doctoral student in epidemiology at Harvard, where Dr. Ratey teaches) and Dr. Ratey, called “Physically Active Play and Cognition, An Academic Matter?”  In it, they describe some of the argument for physical activity, in however a reductionist and atomistic manner.  I don’t want to deal with the entire article, but would like to focus on one point made in it.  Particularly, that “Animal and human research primarily supports the importance of aerobic activity to enhance cognitive function” (pg 369).  There are no references provided to support this statement, and it seems very strange to me.

My question relates to the specification for aerobic activity versus anaerobic activity to realize the vast number of benefits afforded by exercise, or, really, where the distinction or line is drawn between aerobic and anaerobic play for the purposes of this paper.

My understanding of the concept is that there are three types or “levels” of respiration that occur in the human body – cellular (intra-cell, glucose-to-energy), internal (inter-cell), and external (air-to-lungs).  As far as I know, “aerobic” means that metabolic processes occur using oxygen, while “anaerobic” processes occur in the absence of oxygen molecules.

In exercise physiology (particularly, for me, when working with my clients), there are two ways that I recognize whether or not someone is training “aerobically” or not – 1. They’re able to pass the “talk test” – that is, they can keep up a conversation with me while they’re working; and 2. They can maintain their level of exertion for 30 seconds or more.

While the talk test isn’t always accurate, it appears to be fairly reliable.  The second method is a little more “scientific,” since I’m relying on my understanding of cellular (particularly muscle-cell) energetics.  As the intensity increases (either the frequency or severity of contractions), metabolism works to maintain the homeostasis of the cell.  When metabolism can’t keep up, and oxygen is unable to make it into the cell at a sufficient rate to fuel cellular reactions, it goes into “anaerobic” metabolism.  30 seconds is an arbitrary number, but seems to work for most of my clients.

The common understanding of “aerobics” is long, slow, distance exercise, that can be maintained for up to an hour or more – such as jogging, aerobics/group-exercise classes, etc.

However, weightlifting activity can be maintained during aerobic cellular action.  This is often done using weightlifting circuits, where exertion is circulated among different muscle groups throughout the exercise session to avoid total fatigue of a particular group.  Also, heavy bouts of anaerobic weightlifting result in increased post-exercise oxygen consumption (aerobic metabolism) over/above the increase experienced from a similar-duration aerobic activity.

In light of my understanding of human evolution, every type of muscular action or metabolism has its place.  As animals, we had to be able to sprint, sometimes for long distances, to avoid danger.  Similarly, we had to be able to maintain long-duration activity when tracking animals, or moving to new territories.  We had to be capable of lifting very heavy things at times, as well as lifting or carrying light things for long periods.  Is there evidence to support strictly “aerobic” activity as a sole or preferential stimulus for brain development?  It seems to me that the activity shaped the brain.  And if that’s the case, then the same rules for growth now would apply as then – the rules that determine growth in anything – the more varied the stimulus (before sheer erratic randomness), with sufficient time for recovery (here – mental and physical, if you have to make that distinction, which I think is arbitrary), over a sufficient period of time, the more adaptation (“learning”) occurs.