John Seal dispelled the adage that "nice guys finish last" in leading his teams. He was always good to his wrestlers and demanded the most from them while making the sport fun for them and treating them like sons. 

He starred in football and wrestling at Marple Newtown High School. After graduation he followed in his father's footsteps and attended Macon Military Academy, where he captured the Virginia private school state wrestling title. That success led to a scholarship at Appalachian State University, where he wrestled for Steve Gabriel, whom he considered a mentor.

Seal was hired in 1973 by legendary athletic director Brownie Cummings to teach physical education and coach wrestling at Harrisonburg High School. For the next 18 years, he built a powerhouse wrestling program. Under his leadership, the Blue Streaks won 15 Valley District championships and were perennial contenders at the regional and state level, including a state runner-up team finish. He coached seven individual state champions, many state place-winners, and sent multiple athletes on to compete at the collegiate level. 

A member of the Harrisonburg High School Athletic Hall of Fame, Seal also coached boys tennis at Harrisonburg from 1987-91, winning the state championship in 1991, as well as junior varsity football and girls softball during his career.

Seal started a youth league, which has continued to provide the Blue Streaks and wrestlers in the Valley District with experienc. Thanks to his efforts the bar was raised and the Valley District continues to be one of the most competitive in the state of Virginia.

He retired from coaching in 1991 and continued his service to Harrisonburg City Public Schools as an administrator, overseeing physical education, family life education, health education, school nursing, driver education, drug and substance abuse, school nutrition, and other programs until his retirement in 2004.