Sedentary Behavior! by Ross VonGlahn, PT, DPT

For further information, I recommend you reference the perspective article below by Wheeler et al, 2017 from the journal, Alzheimer’s & Dementia: Translational Research & Clinical Interventions, titled Sedentary behavior as a risk factor for cognitive decline? A focus on the influence of glycemic control in brain health.

Intro

Many of us know that exercise is good for you. However, the effects of exercise go beyond just looking good and feeling good. New research is being conducted, looking at the effects of exercise and disease prevention. However, is exercise enough? New literature suggests no. The benefits of exercising for the recommended 150 minutes per week may be cancelled out by sedentary behavior (sitting/laying) the rest of your waking day. Think about it. How much sitting do you do in a day? One hour? Five hours? Eight hours? Take some time to actually tally this up between driving to and from work, sitting at work, sitting for meals, and sitting in front of a screen. The number may surprise you. A survey by the U.S. National Health and Nutrition Examination Survey shows that on average people are sedentary greater than 9 hours per day, perform light activity 5 hours per day and perform 11.3 minutes of moderate to vigorous activity per day. Of the 150 minutes per week of recommended moderate to vigorous activity, nearly one-third of people do not meet this recommendation. The number of people not meeting this recommendation increases as age increases as well.

What is it about?

This article reviews the physiologic processes involved in regulation of glucose (sugar) in the brain as well as the effects of abnormal glucose levels in the brain. Glucose is the primary fuel for the brain and is essential for the proper functioning and health of the brain. When blood sugar is too high, the brain will regulate this by decreasing blood flow to the brain as to decrease the overall amount of glucose to the brain. When it is too low, the brain struggles to have enough energy source to work efficiently and may cause damage known as apoptosis (cell death). Also, when your brain accustomed to high glucose levels (hyperglycemia), it can experience relative hypoglycemia when it returns back to normal blood glucose values, leading to damage.

Why does this matter?

Think about eating a big meal, full of carbs and sugar. You will have a large spike in your blood sugar, which signals the brain to decrease blood flow to the brain, as well as release insulin from the pancreas. The insulin helps drive glucose into your cells, effectively lowering your blood glucose (ie, blood sugar). However, this tends to overshoot and leads to a “hypoglycemic event” as referenced in the above article. This hypoglycemic event can lead to apoptosis (cell death) in the brain. This is a process involved in Alzheimer’s and Dementia. They cite that those with type 2 diabetes are 50% more likely to develop dementia compared to those with normal blood sugar control and regulation.

Tying it all together

Reviewed in the above article, sedentary behavior increases the risk for diabetes and poor glucose control. By decreasing sedentary behavior, an individual may better regulate the hyperglycemic events that subsequently lead to a hypoglycemic event and causing damage to the brain. Limiting this undulating pattern of high blood sugar to low blood sugar may limit the damage to the brain and maintain brain health. It recommends that outside of the recommended 150 minutes/week of exercise, intermittent walking or light activity throughout the day may help control blood sugar and maintain brain health. Point of the story is, get up and move and move often.