Although its legitimacy is often called into question, competitive marching band is sometimes considered a sport, due in large part to the physical exertion required in combination with teamwork. Many HBCU marching band fans refer to marching band as "marching sport." Sports Illustrated considered the activity a sport in 1987, describing the Drum Corps International World Championships “one of the biggest sporting events of the summer.” In the same article, Sports Illustrated quoted basketball coach Bobby Knight, "If a basketball team trained as hard as these kids do, it would be unbelievable. I like to take my players watch drum corps to show them what they can accomplish with hard work and teamwork. Besides, once they see them practice 12 hours a day, my players think I’m a helluva lot easier.”