Board Thread:Theories and Speculation/@comment-26138683-20150322132758/@comment-4912646-20150322200510

Cookie Montser wrote: So if chakra is the combination of Yin and Yang, does that mean your chakra stores reduce as you get older because your Yang chakra reduces, even if your Yin increases, since the 1:1 chakra combination won't be possible anymore (leaving an excess of Yin)? And does that mean as you get older and older, your genjutsu ability increases?

Physical energy decreasing with age makes a lot of sense. We know that increasing either physical or spiritual energy increases your overall stamina/chakra from the fact that Hashirama's cells were specifically said to increase physical energy (by Obito I believe). So it makes sense that the same energy decreasing would drastically lower one's chakra reserves. This could also explain why clans like the Senju and Uzumaki have a large amount of chakra, having inherited Asura's life force and physical energy genetic traits.

On a side note, is "chakra reserves" an actual term from the series or just a fan term? The chakra article says one's total chakra is their "chakra power level" but I'm certain terms other than that have been used to describe it before.