Health Education: inactivity

Something we hear often when health experts discuss the rising rates of both obesity and diabetes is that the population as a whole has become more sedentary (less active) over time and that this change in activity level is contributing to the problem. In January I mentioned research that supported this assertion and in fact, suggested that even daily runners were at risk for heart disease and other health problems if they spent the rest of their hours being relatively still. A NY Times journalist (Olivia Judson) offered a similar post in February, but she graciously ended her piece with a bibliography of several research studies. One of those studies, Role of Low Energy Expenditure and Sitting in Obesity, Metabolic Syndrome, Type 2 Diabetes, and Cardiovascular Disease. Marc T. Hamilton Deborah G. Hamilton and Theodore W. Zderic, offers insight into what exactly happens when we spend all this time on our bottoms. Ms. Judson suggests that we have 15 hours of time not spent sleeping that we can spend active or inactive. The researchers mentioned above actually did a little reverse science. There is ample data to show what happens to us physiologically when we exercise. We know about heart rates and endorphins, oxidative stress and oxygen consumption, as well as calorie expenditure and sleep stasis – we have no doubt that physical activity, especially frequent and intense exercise – prevents disease and disability. What about the opposite? What happens on a molecular level – what happens inside our cells, tissues and organs – when we are still for extended periods of time? As it turns out – our metabolism changes and we actually use and store sugars and fats in ways that cause harm. I like the phrase that the researchers use when discussing their study – they call it “inactivity physiology”. They admit that there is not a lot of study into this phenomena and that it is a great place to spend some research time and dollars. Hamilton, et al offer four tenets of inactivity physiology – The first is the idea that there is a curve of wellness associated with extra physical activity. We may be at the middle (an average, fit persons) and our health improves or shifts to the right, when we exceed the 30 min of activity/day that is often recommended – but does it shift to the left if we do not even do the 30 mins? (most of us agree this has been shown to be true) . The second tenet is that the episodes of sitting and the episodes of focused physical activity have very distinct effects on our bodies. Meaning, even the most active person’s body has an adverse biological response to being still. The third tenet suggests that the adverse effects of sitting for too long are not simply the reverse of the positive effect of a 30 minute walk. That sounds like tenet two, but I think it to mean something a little different. There may be a specific way that exercise boosts HDL which does not mean that sitting just prevents higher HDL – sitting too long may affect cholesterol in a completely different – but harmful way. The fourth tenet has to do with large groups of people, or cohorts, who are aging together in this sedentary mode and the increases in heart disease, diabetes, obesity and more that will occur in large numbers. It is of vast importance to get these people moving, especially if we are talking about a cohort of third graders! The article is a big read – you are welcome to <a href="http://diabetes.diabetesjournals.org/content/56/11/2655.full">view it here</a>. The take home message however is this – get up and stretch or move about every hour that you are not asleep and you will reduce the negative metabolic actions that sitting too long can activate.

Let Not Your Limbs Be Idle

Something we hear often when health experts discuss the rising rates of both obesity and diabetes is that the population as a whole has beco...

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Let Not Your Limbs Be Idle

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