Abstract: An insole having a thin baseplate with a surface that is tightly nubbed. Breathing openings are disposed between the nubs. Magnetic heads are fastened, preferably releasably, on the baseplate. The baseplate is thickened in the area of the magnetic heads. This thickened area has a surface which is not nubbed. The thickening is preferably drawn to at least the level of the tips of the nubs. Such an insole, which only has a total thickness of approximately 3 mm, can be worn in all commercially available shoes and boots. The insole can also be employed particularly advantageously in athletic shoes.