The Compendium of Caraka 1.6.8

1.6.8

bhavati cātra
ādāvante ca daurbalyaṃ visargādānayornṛṇām /
madhye madhyabalaṃ tvante śreṣṭhamagre ca nirdiśet //

And here it is said:
Weakness is in human beings at the beginning and the end of the releasing and debilitating periods;
in the middle, moderate strength should be stated; but at the end [of the releasing] and at the beginning [of the debilitating], maximum [strength].