Hai is a training method of taikiken, but it can apply to various martial arts exercise except for taikiken. It is considered that Hai is very important training method to keep lower body stable without shaking, and center of gravity of body lower and perform weight transfer smoothly. This training method is recommended to the people who play kendo and have a symptom when player crash opponents player foot wobbling and become weak to step on . Moving speed of Hai is more slowly than you imagine and at first it seems to be impossible to perform hai as fast as the pace martial arts book write that.
It is very slow so that you have to count times with your mouth at first. Performer advance with one side of foot on the ground and another side of foot just above the ground as well as you can. At first performer have possibility to pain his waist but performer should continue doing as well as he can. If performer can not continue doing so, he should have a break. After you continue hai exercise every day, gradually leg sensation begin to change and he can move nicely and easily. Performer continue hai exercise every day, he can acquire delicate and strong legs and waist.