Charles did not learn to speak until the age of four nor to walk until eight,[1] and was treated as virtually an infant until he was ten years old. Fearing the frail child would be overtaxed, his caretakers did not force Charles to attend school. The indolence of the young Charles was indulged to such an extent that at times he was not expected to be clean. When his illegitimate half-brother Don John of Austria, a natural son of Philip IV, obtained power by exiling the queen mother from court, he covered his nose and insisted that the king at least brush his hair.
The only vigorous activity in which Charles is known to have participated was shooting. He occasionally indulged in the sport in the preserves of the Escorial.
Basically the King of Spain spent most his reign literally shytting his pants.