Is there a difference between the ratio of type 1 over type 2 in different muscles? For instance, leg muscles which would 'naturally' (an average human being, not the sporty type) be more used for walking or running long distances..maybe related to an evolutionary genetic aspect in the sense that historically we didn't have cars before 1900...?
To be honest, I'm not sure about that, but I'd say your theory sounds correct. Also, humans are bipedal unlike most species, so we would definitely need more endurance in our legs to be able to stand/walk etc. for long periods. And yes, the ratio is different for different muscles, which is largely determined by individual genetic differences.
But it has been shown that type 2a fibers can be turned into type 2x fibers, why would type 1 fibers not turn back to type 2a fibers. From an evolutionary point of view, that doesn't make any sense. Also, there are hybrid fibers. So Type 1/2a and 2a/2x hybrids for example. Those make up most of the muscle, since pure 1, 2a or 2x fibers are much rarer than hybrids. Those hybrids have the function to convert into one of the types you need more, so 1/2a hybrids will become more 2a when you do strength training and 2a/2x hybrids will become more 2x if you do powerlifting.
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Is there a difference between the ratio of type 1 over type 2 in different muscles? For instance, leg muscles which would 'naturally' (an average human being, not the sporty type) be more used for walking or running long distances..maybe related to an evolutionary genetic aspect in the sense that historically we didn't have cars before 1900...?
To be honest, I'm not sure about that, but I'd say your theory sounds correct. Also, humans are bipedal unlike most species, so we would definitely need more endurance in our legs to be able to stand/walk etc. for long periods. And yes, the ratio is different for different muscles, which is largely determined by individual genetic differences.
The answer is yes.
But it has been shown that type 2a fibers can be turned into type 2x fibers, why would type 1 fibers not turn back to type 2a fibers. From an evolutionary point of view, that doesn't make any sense. Also, there are hybrid fibers. So Type 1/2a and 2a/2x hybrids for example. Those make up most of the muscle, since pure 1, 2a or 2x fibers are much rarer than hybrids. Those hybrids have the function to convert into one of the types you need more, so 1/2a hybrids will become more 2a when you do strength training and 2a/2x hybrids will become more 2x if you do powerlifting.
What does type 2 dx means some combination of type 1 type 2 ?