Ionized water is fundamentally different from conventional water. Compared to the propensity of conventional water to consist of large clusters of water molecules, ionized water exhibits a smaller molecular cluster size.  
The ionization process changes the water cluster structure from larger irregular shape to a smaller regular hexagonal shape.
 
Ionized water consists only of 5 - 6 water molecules per cluster whilst conventional water consists of 10 ~ 14 water molecules in a cluster.
 
It is a superior hydrator:

Ionized water passes through body’s tissue and cells more easily, penetrates better and pushes out toxins and acid wastes more effectively. 
The smaller clustered water also reaches tissues in the body, that ordinary water cannot access due to its bigger cluster size. Better hydration, means better supply of fluids to all the vital organs, tissues, cells, better hydration means better functioning, more energy, more vitality.
 
It improves Detox: this also means better elimination. Better absorbance of water accelerates  the rate of dissolution and excretion of waste products (such as metabolic by-products and other forms of toxic waste accumulated from the external environment) in and from the body by about three times.
Better elimination also means that cells and tissues can recover faster from toxid waste, and experience rejuvenation.
This reduces inflammation, pain. It increases the healing  process, the recovery time from illnesses is faster.
 
 
Comparison of water molecular cluster size - By NMR test

Alkaline ionized water	54 Hz	Mineral water	94 Hz
Municipal water	120 Hz	Well water	105 Hz
Longevity (long life) village water	80 Hz	Distilled water	118 Hz
Hot spring (spa) water	80 Hz	Natural water	122 Hz