User blog comment:Soulreaper1234/What's up with Ichigo and his BANKAI, is it in constant release?/@comment-44061-20100915050543/@comment-1961713-20100915052225

Then how can Ichigo's spiritual body goes tad taller and hair bit longer while Isshin grows his beard and moustache in 1 hour, that does not count even when they are not really battling? In order to achieve those level you must have the ability to constantly release or maintain that power level to undergoes this type of dangerous training, can Renji, Rukia and the others achieve this? Compressing this reiatsu would be a burden even for a few hours.