At 71, still an olympian.

Hiroshi Hoketsu of Japan became the oldest competitor at the 2012 London Olympics on Thursday when his horse Whisper cantered into the ring at the equestrian dressage competition at Greenwich Park. The 71-year-old Hoketsu was also the oldest competitor at the 2008 Beijing Games. An even greater feat may be that it's been 48 years since his first Olympic appearance. He competed in equestrian show jumping at the 1964 Tokyo Games. "The biggest motivation I have to keep competing is that I feel I am improving," Hoketsu said. Hoketsu scored 68.72 percent in his Grand Prix dressage test on his 15-year-old chestnut mare, putting him in the middle of the pack of the day's 25 riders and out of medal contention. "I made two or three mistakes, which I shouldn't have," he said. Dressage is a sort of equine ballet where the horse performs elaborate gymnastic movements to subtle cues from its rider. After the Tokyo Games, Hoketsu stepped back from competition and earned a master's degree in economics from Duke University. Next came a business career in Japan but he still rose daily at 5 a.m. to ride before heading to the office. After he retired, the 5-foot-6 Hoketsu renewed his Olympic equestrian aspirations and begantraining in earnest in Germany. Hoketsu is currently the second-oldest Olympian ever. Oscar Swahn won a silver medal in shooting in 1920 at age 72. Hoketsu could break Swahn's mark at the 2016 Rio Games, but he doesn't plan to do so -- not because of his own energy level but for a lack of horsepower. "I want to but I can't," Hoketsu said. "It's difficult to find a horse, and mine is now too old." The second half of the competition's 50 riders will perform their dressage test on Friday. The scores will carry forward to a Grand Prix Special test on Tuesday to determine team medals and a freestyle performance on Aug. 9 to decide individual medals.