A study in 2006 compared the speeds of Quarter Horses, Thoroughbreds and Arabians and found that, over short distances, Quarter Horses were faster than Thoroughbreds. Arabians were quickest at longer distances because they are bred for stamina. A fast Quarter Horse can achieve speeds of around 89 kilometres (55 miles) per hour. Although the Quarter Horse is considered to be the swiftest breed, the fastest speed for a race horse is credited in the Guinness World Records to Winning Brew. In 2008 this Thoroughbred filly hit 71 kilometres (44 miles) per hour.