AYI - Ask Your Instructor

The answer to most, if not all questions regarding Ninjutsu (arguably all martial arts) is ask your instructor. If you dont have one then unless you are a SOKE or a KANCHO or an ANSHU (or something simular - head of your your art/dojo/system) then YOU ARE NOT A STUDENT OF THE MARTIAL ARTS - you are an observer, a spectator, a visitor, a distant aunt who visits on a sunday - (don't ask I need sleep). If you want to be a martial artist (unless you are the head of your art) then go and get an instructor, or join an organisation where you can learn from your instructor or peers.

Just my humble opinion.