Isadore Channels’ interest in tennis grew when she moved to Chicago as a teen. In 1919, Channels started her training at the Prairie Tennis Club. Co-owned by Mary Ann “Mother” Seames, the club was frequented by the best Black players in Chicago. Channels was a naturally gifted player, quickly becoming very skilled at the sport. The Chicago Defender newspaper later described her rise to the top of competitive tennis with such little training as being “most remarkable.”

By July 1920, Channels had won Chicago’s Black championship, ending Mother Seames’ eight-year winning streak. Channels won again the following year and she reached the women’s singles final of the ATA National Championships. In 1922, Channels won her first ATA singles title at the National Championships in Philadelphia, defeating Lottie Wade in the finals. Channels won the National Championships again in 1923, 1924, and 1926. She was the first woman to win four ATA Championships. 1924 was an especially remarkable year for Channels, as she won the Women’s Doubles Championship with partner Miss Leonard and reached the finals of the Mixed Doubles Championship as well.

Channels, like Eyre Saitch and Ora Mae Washington, was a star basketball player as well as a tennis champion. In 1920, she helped establish the Roamer Girls amateur team in Chicago. The Roamer Girls was the among the first Black women’s amateur teams. It was also the first Black team to compete alongside White teams in a league, the Windy City Basketball League. Meanwhile, Channels attended Phillips High School. She became the school’s captain of the basketball team in 1925 and coached the school’s intramural girls’ tennis club. In 1926, Channels graduated from Phillips and temporarily retired from basketball. She and her teammates remade the team on multiple occasions, the first time being for the 1929-1930 season.

In 1927, Channels moved to Roanoke, Virginia and began studying at a nursing school while continuing to play tennis competitively. Channels’ singles rankings were No. 4 in 1929 and No. 5 in 1930.

By 1934, Channels was no longer playing tennis competitively and she instead worked as a nurse full-time in various cities throughout the southern United States. Toward the end of her life, she worked as a nurse for the Lincoln School in Sikeston, Missouri.

In 2011, Channels was inducted into the Black Tennis Hall of Fame.