why “no excercise = tiredness” but “excercising = energy”




In: Biology

Simply put, the more active you are the more mitochondria your body produces. It’s like a domino effect. The more you exercise, the body makes more mitochondria to make more energy. Just reply if you need a more in-depth answer.

Your body adapts to the demand you put on it. If you do exercise then you “level up” and basic tasks like walking around or just staying active/awake become easier too.

Isn’t the premise of the question wrong? Serious exercise is going to make you tired. During the exercise and immediately afterwards you’ll probably feel wide awake because of all the stress hormones and stuff, but an hour or so afterwards you’ll definitely feel exhausted and tired (or at least not more awake than without the exercise).

Of course if you are in bad health (either physically or mentally) due to lack of exercise it can help you long-term.

Edit: Why am I getting downvoted? Is anyone seriously questioning that you’ll feel tired after serious exercise? Just go out and do some exercise at more than moderate intensity for more than half an hour. Of course you won’t feel tired after a 20 minute easy walk.

Tl;dr – supercompensation and progressive overload.

Your body is actually pretty adaptable to the situation around you, and will do it’s absolute best to make sure you are just about capable to handle the largest stresses you meet on a regular basis. The way it does so is by rebuilding your body sliiightly stronger than it was after you do something very hard. This is called supercompensation.

However, we have a problem: this effect does not last very long. But if you excersise again during this window, you get the same effect, stacked “on top of” the first. To get better, you have to keep exposing your body to gradually increasing stresses (run faster or longer, lift heavier, etc). This is called progressive overload.

These two terms are the cornerstone of every well-designed excersise plan. In time, the stresses of your daily life will no longer be as tiring as they used to be, and you will be less tired because of it.

This has to do the with arousal systems in your brain. Exercise releases cortisol and adrenaline and activates the sympathetic nervous system (increased heart rate, increased alertness and arousal) and activates the reticular activating system.

That makes you feel more awake . Also release growth hormone and other endocrine things.

Among other things which have nothing to do with load or mitochondria. Or stacking. Or supercompensation (all of these ar bro science and not actual science).

Think of it this way. Humans (not all animals but humans in particular) have a really use it or lose it policy. If you dont need to pay attention, because ain’t nothing happening, then conserve the energy and be quiet and don’t move. Another way to think about it is that up until the last couple hundred years you would have been having to move around at least a little bit to do anything at all -even the easiest of cooking would have required poking a fire, stirring while separating your warring children , and peeling off inedible parts from edible parts of plants. So not weightlifting but you would have been walking and moving almost conststantly. Untill it was time to go to sleep. When the long time of inactivity signals the depression of the reticular activating system so that you can do that.

It is only with the advent of very modern living that you would have ever really been able to be totally still except your thumbs while scrolling for any really long time.

I’m incredibly active but I also always have zero energy. Low T possibly?

Stress + Recovery = Adaptation

Your body simply adapts to the conditions it is subjected to regularly.

There are a lot of medical reasons given here, along with ‘technical’ talk. But, I would say a simple explanation that is not technical is: exercise increases your metabolism.