The practice of Sanchin creates great ki, teaches proper breathing, and develops strength in the muscles and bones. The practice of Sanchin unites these three into one. The exact meaning of "Sanchin" is; San means three and Chin means combat thus we get "three battles".

Three is a significant number. Starting with the name, i.e. san means three. We also have the combination of ki, breathing, and muscle. Then we also have the three areas of the body; the jodan area or upper body, the gedan area or middle of the body, the gedan area or the lower body.

Jodan: represents the spirit developed by the practice of Sanchin.
Chudan: represents the breathing aspect of the practice of Sanchin.
Gedan: represents the rooting to the earth or the stance aspect of the practice of Sanchin.

Externally Sanchin works from the toes up to the top of the head.

In addition three represents that which is developed in the practice of Sanchin; Strength, Coordination, and Spirit. Three also represents the unification of focus, speed, and strength which is another benefit of the practice of Sanchin.

The practice of Sanchin develops both internal and external strength.

When you combine the three sets of three of Sanchin you get nine which is also a significant number.

KI - BREATHE - SPIRIT
FOCUS - SPEED - STRENGTH
JODAN - CHUDAN - GEDAN

Sanchin Shime:

Shime's purpose to train the student as well as test their muscle/bone, breath, coordination, focus, strength, posture, and so on. It also helps the student to become aware of the parts of the body and shows them the effectiveness of the Sanchin practice. It also helps them to see the progress of both the mental and physical power created through Sanchin practice and Sanchin shime.

Always start from the lower part of the body, i.e. the feet, and work your way slowly up to the shoulders. Use the hands to touch for correctness and the flat of the hand if striking. Never use the fist or ball of the foot as these are used in demonstrations only.

Sanchin shime helps the student to see, and more important, feel the kata. It helps them see and feel their progress as they practice. One of the great benefits of the kata, or any kata for that matter, is it is practiced always and forever as there are constant improvements that can be made depending on the time of day and the condition of the practitioner at any given time in their lives.

Life is full of constant change or in flux so practice of sanchin will also change depending on the date, day, time, physical and mental condition of the practitioner.