Fake Tiredness

I think it's relevant to say a few words about why we feel tired and how sedentary hibernation can impact our productivity and wellbeing.

Many may believe that tiredness or fatigue results from us completely exhausting our resources. It turns out, however, that we get tired way before we drain all of our energy. It’s a protective mechanism used by our bodies to protect us from over-exertion, which would be dangerous for a human – or any other animal in the wild. Our bodies always make sure that we have enough energy left at all times in case we need to run away from a predator.

You have probably heard that our bodies turn on the “fight or flight” mode when we are in dangerous situations. What you may not know is that it starts by releasing a cocktail of hormones into the bloodstream. One of the most well-known hormones that we get served is adrenaline.

Among other things, adrenaline increases the heart rate and blood pressure, expands air passages in lungs, and alters the body’s metabolism, maximizing blood glucose levels to help our brains think fast and give our muscles energy to sprint or fight. Even if you felt extremely tired just a second ago, you would be surprised how fast you could run with an approaching tiger in sight.  

So, let’s get back to sitting.

Our brain uses a distributed network of sensors spread out all over our bodies. I imagine, it is aware of and pays particular attention to what happens in their vicinity. Our bodies are wired to activate appropriate energy sources depending on the physical activity in which we are currently involved, ranging from high-intensity performance to maintaining prolonged, low-intensity work. It’s believed and widely accepted that our brains’ preferred energy source is glucose and oxygen; in other terms, they rely on the aerobic energy pathways. The lack of one or both due to diminished blood flow or poor oxygen saturation in the blood may lead to an inadequate energy supply. As our bodies sense that there’s not enough “food for thought” (pun intended), they assume that we are at the brink of complete exhaustion, flipping the switch to save energy, just in case you need that energy to fight or flight later on.

Do you see how twisted this is? As you sit down, your blood flow slows down, and the supply of oxygen and nutrients carried to your brain may also decrease. While you work or study, you brain needs more energy to compute, but, instead of giving you more energy, your body claims it by making you tired, unwilling to do anything. Weird, I know! But also quite natural.