The Body is a Warrior's tool. By building a strong Body you manufacture a solid base from which Power emanates.

Body is one part of the trio of values of character that you try to build, these three aspects representing what it means to be a Warrior are summed up in the concept of Shin Gi Tai, the other two being Katachi and most importantly the Mind.

You build the Body through Keiko.

On the hierarchy of values within Shin Gi Tai, the Body is the base, followed by Katachi, ruled by the Mind.

For this reason it is most essential that you build Power via Keiko, of which the cornerstone is Power Lifting. Body as the Power base will enable you to follow through to a higher level - building the Mind.