At this level, the mixing, transformation and harmonization of energy takes place in the solar plexus.
The increase in power results from the fact that the second formula draws the yin and yang energy from the body itself, while the third formula draws the power directly from the sky (above) and from the earth (earth line - corresponding to yang and yin), adding these elemental forces to those of the body. In fact, the force can be drawn from any energy source, such as the moon, a forest, the earth, light, etc.