Markus Bagley, 4, began tae kwon do lessons at age 2. The boy from Avenel, New Jersey, quickly punched his way through six belt levels by following detailed commands in Korean. Last month, he earned his brown belt. Now he's only three away from the top belt, black. Markus trains with teenagers and often defeats older kids in competitions. "I do it because I love it," he told TFK.