ARCADIA, Calif. - Exercise rider Arturo Mares was hospitalized on Saturday with serious injuries after he was involved in a one-horse spill during morning training at Santa Anita, according to trainer Hector Palma. Mares, 64, was taken to nearby Huntington Memorial hospital for treatment, and was on a respirator, Palma said. :: Access morning workout reports straight from the tracks and get an edge with DRF Clocker Reports Full details of Mares’s condition was not immediately available. Palma said he had been in brief contact with Mares’s family on Saturday. “It was a freak accident,” Palma said. “The horse was jogging and he stumbled. [Mares] fell off. “We hope everything changes for the best.” According to witnesses, Mares was treated by paramedics on the track before he was transported to the hospital. - additional reporting by Brad Free :: Want to learn more about handicapping and wagering? Check out DRF's Handicapping 101 and Wagering 101 pages.