At the 1972 Games in Munich she won a silver medal in the 4 × 400 m relay with teammates Mable Fergerson, Kathy Hammond, and Cheryl Toussaint.

[2] In 1965, while she was a student at John Hay High School in Cleveland, she won her first national title in the 440-yard run at the girls' AAU championships.

[2] Manning is founder and president of the United States Council for Sports Chaplaincy and has been a chaplain at the 1988 Seoul, 1992 Barcelona, 1996 Atlanta, 2000 Sydney, 2004 Athens, and 2008 Beijing Olympic Games.

She also has a ministry through sports and the arts known as Ambassadorship, Inc.[3] She is also an author, speaker and contemporary gospel recording artist, who was inducted into the Oklahoma Jazz Hall of Fame in 2005.

After briefly retiring from the sport, she returned running with anger and frustration, to the point that her coach had to train her separately from other athletes on her team and had to ask her to slow down.