He attended Michigan State Normal College from 1910 to 1914 and played for the football, baseball, and basketball teams.

Over the course of his career, he coached at least one year in every varsity sport at Michigan State Normal, including football, basketball, baseball and track.

During a four-year stretch from 1917 to 1921, he led the basketball team to a combined record of 48–9, including a one-loss season in his first year as the coach.

[6] Rynearson suffered a heart attack on January 28, 1967, and died one week later at St. Joseph Hospital in Ann Arbor, Michigan.

The Eastern Michigan football program has played its home games at Rynearson Stadium since the 1969 season.

In 1976, Rynearson was posthumously named one of the inaugural members of the Eastern Michigan University Athletic Hall of Fame.

Although Rynearson's offense was more effective, outscoring opponents 111 to 82, more than half of the scoring came in a single game, a 63–0 rout of Central Michigan, and the team ended the season with a 3–4 record.

[15] During a four-year stretch from 1917 to 1921, he led the basketball team to a combined record of 48-11, including a one-loss season in his first year as the coach [1] and the Michigan Intercollegiate Athletic Association Championship in 1921.