Boxing legend Larry Holmes and former football star Herschel Walker are welcoming continued research on the impact of blows from boxing and other sports on the athlete's brain.

The two joined Sen. John McCain of Arizona and Dr. Charles Bernick of the Cleveland Clinic's Lou Ruvo Center for Brain Health on Tuesday at a Capitol Hill news conference. Bernick announced that the study would continue for another two years and that the Nevada Athletic Commission will require all fighters to undergo regular brain testing.

Holmes, the former heavyweight champion, said in a career that spanned 75 fights, including 69 wins, he never intended to hurt anyone. But the sport takes its toll.

Walker, a star running back involved in the mixed martial arts, called the research a blessing.