Prince William may not be running a marathon in Kenya any time soon, but he fit in a race with Kate Middleton and Prince Harry on Sunday, People reports. The three visited the London Marathon Community Track at Queen Elizabeth Olympic Park to meet with 150 runners. The athletes will participate in the London Marathon to raise money for Heads Together , the Royal Family's mental health charity. They spoke with the team about how they and the event's 38,000 runners can promote mental health. Paula Radcliffe , who's won the London, New York, and Chicago marathons, joined them. It wasn't all serious, though. Prince William goofed around as he, his wife, and his brother competed in the first 50-meter leg of a relay race. "Oh, my hamstring!" he joked while holding his leg before they began. If he was trying to throw his competitors off, it worked, because he came in first, followed by Harry. It was close, though, which he acknowledged by yelling to Kate, "You nearly beat me!"