Ok, ok. I truly don’t mean to beat you over the head with this concept, but I’m going to anyway. I think we’re approaching exercise all wrong.
The problem is that, if I’m right, this isn’t some little tidbit that doesn’t make a difference. All of our public health recommendations need to be revamped.
Let’s face it, the standard “30 minutes of walking most days of the week” just isn’t cutting it. And yet you probably drive by several people per day who appear to be walking around the block at a leisurely pace, likely carrying that beloved plastic water bottle.
If you go to the gym, the treadmills, exercise bikes, ellipticals, rowing machines and aerobic classes are full of people logging in hours and hours of constant-stream aerobic activity.
Despite the evidence, the American Heart Association and the American Diabetic Association remain silent on the value of short-burst aerobic exercise.
This particular article is written in Medical Hypothesis, a journal containing articles written by forward-thinking scientist. Some may be way off the mark, others are later shown to be right on. Still others merely put together all the pieces from across the world of research and come to conclusions before anyone else even notices that there is a puzzle.
Dr. Cherkas and Dr. Golota begin to put the pieces together by first looking at the short-burst aerobic picture from the context of glycogen.
Glycogen is a molecule made up of multiple pieces of glucose. Most of the glycogen in our bodies is stored in either the liver or in our muscles and is used quickly for fuel when we first begin to burn calories (such as while exercising). After we eat, the hormone insulin tells our liver and muscles to take the glucose (sugar) from the meal out of the blood and store it as glycogen.
Later, the hormone glucagon is released from the pancreas, which results in a slow breakdown of the stored glycogen in the liver so that the rest of the body can have a stable source of glucose until the next meal.
Short burst aerobic activity burns through ATP (the energy currency of the cell), then creatine phosphate, then glycogen is broken down into glucose molecules for fuel. Because this leaves the cell starving for more glycogen, the next exposure to glucose (such as after a meal) is going to lead to increased uptake of sugar from the bloodstream and into these glycogen-depleted cells.
When we start to look at additional pieces of the chronic-disease management puzzle, calorie restricted diets and intermittent fasting have much the same effect on glycogen stores, again leaving your cells hungry to grab the extra glucose from the next meal.
With this in mind, you can begin to see how many of these approaches to disease management and / or longevity end up having similar effects on glycogen storage in the liver and muscles. On the flip side, without this depletion of glycogen before the next meal, if the cell is already full of glycogen, glucose taken up at this point will get stored as fat inside the cells.
More fat inside the cells leads to unhealthy cells (fatty liver, intramyocellular lipid accumulation) and higher risks of chronic diseases. Not a good thing.
Overall, I thought it was interesting to connect calorie restriction, intermittent fasting and short burst aerobic activity via glycogen use and storage.