They say yoga helps to develop fully human capabilities. It is different. And yoga of the mind and yoga of the body. If you are interested, I advise you to read Patanjali's yoga sutras first (I hope he named it correctly))
A person can be compared here with an engine. 100% is the level of possible peak load, red zone. A person, like an engine, is not designed for constant operation in this mode, this leads to premature wear.
Numerous attempts to create a "universal soldier" who does not sleep, does not feel pain, does not get tired and thinks well, until they were crowned with success. Short periods of such activity are replaced by very disturbing disorders of the work of internal organs and psyche.
However, since 100% is not an absolute criterion, this bar can be pushed back, thereby increasing your potential for critical situations. The methods are very specific and depend on what characteristics you want to develop.
More or less true. Look here: now you are reading, ie somehow use your ability to read and understand, but do not use your abilities at all for running, swimming, solving math problems, etc. etc. If you do not go into details, then in principle we can say that you use your abilities at 1%. If, for example, tomorrow you go to the pool and swim there, then you will use your swimming ability, but not use your reading ability, problem solving (and further down the list). And you will use 1% again, but it will already be some other percentage. In the third situation, some third percentage will be used, well, etc.
If you think that some unclear who took it, used all his 100% at once and became a superman, then no, this does not happen in nature and cannot be.