All are directly affected by exposure to external magnetic fields. Only ions that are moving are affected. Those that are not moving are completely unaffected. The body's ions move very slowly, so even a strong external magnetic field will have little effect. The very powerful magnets in MRI machines can cause tiny changes that the equipment can detect but are temporary and have no known health effect.
Magnets generate a magnetic field that penetrates the skin, tissue and bones.
Studies show this increases blood flow, thus enhancing the body's healing process. The improved circulation has been shown to bring in oxygen and nutrients. Several studies have found that magnets do not increase blood flow. If blood were strongly attracted to magnets, it would tend to pool and might even come through the skin when a person is exposed to the powerful magnets in MRI machines. While magnetic therapy is not effective on everyone, most studies indicate many individuals have benefited from this non-invasive approach to healing.