Eli5: why does your muscles come back bigger after ripping them during workout but doesnt when you cut yourself?
In: 0
The tears are way, way smaller.
A huge amount smaller.
Muscle fibers that are damaged from a workout are measured in micrometers, and are not full cuts through.
First of all, unless you are cutting ridiculously deep, you aren’t cutting your muscles. Even if you were to start stabbing yourself on the daily, the nerve signals sent to the brain when your muscles tear from working out are not going to be the same signals sent when you get stabbed in the muscle.
Imagine you get punched every day in the same spot by the same person. So eventually, you start ducking every time you see that person. That’s the kind of adaptation that occurs when your muscles grow back bigger after working out. They know what’s coming and the body has evolved to prepare for repeating occurrences of its experiences.
Now imagine that you walk past that same person, duck, but this time they shoot you in the foot. Assuming you can’t simply avoid walking past this person, there isn’t much you could do to adapt to that, is there? Unless you have bulletproof shoes, you are just going to have to hope it doesn’t happen again. The same is true for your muscles. Your body knows better than to be fooled by any and all muscle damage. There isn’t shit your body can do to protect you from being stabbed so it just heals the muscle and probably makes you a bit more vigilant in the future. If your body went above and beyond after every injury to make sure it couldn’t happen again, too much energy would be wasted. Hence why we evolved to only adapt to certain sorts of damage, such as muscle damage from too much muscle usage.
First of all, as far as I know, the “micro tear” theory of muscle growth is still debatable.
That said, your body has mechanisms to adapt to certain stresses.
If you spend more time in the sun, your body will adapt by making your skin darker to make you more resistant to sun burns.
If you play guitar, your body will adapt by growing thicker skin on your fingertips on fingers which press the strings to make the skin more resilient to tearing.
When you lift weights, your body will adapt by growing bigger muscles to allow you to lift more weights.
But in order for body to adapt, you need the right kind of stress, stress needs to be of the right magnitude (if it’s too small it won’t trigger the adaptation, if it’s too big it will cause damage) and it needs to happen regularly. If you cut yourself, that’s a very damaging event, and it happens only once.
Lifting weights, on the other hand, is moderate stress that occurs regularly, so your body gets a signal that it needs to adapt to this stress it keeps experiencing over and over again.
Latest Answers