Originally from Council Bluffs, Iowa, Shelly established herself as a top national competitor in the equestrian world. Gaining recognition through the United States Pony Club , Shelly earned two national championship titles and a top six world championship finish in tetrathlon (swim, run, shooting, cross-country equestrian riding).
During high school, she became one of Iowa's premier cross-country runners and excelled at the 400 meter distance. She regards her participation in the prestigious Drake relays on two different occasions as a career highlight. She then competed at the collegiate level in swimming, fencing and soccer at Sweet Briar College, where she also earned a degree in Sports Medicine.
After college, Shelly moved to San Antonio, Texas, since at that time the city held the Olympic Training Center for modern pentathlon (fencing, swim, run, shooting, cross-country equestrian riding). Her pentathlon career peaked with an individual gold medal performance at the 1995 U.S. Olympic Festival.
Following the International Olympic Committee decision not to include women's pentathlon in the 1996 Olympic Games, Shelly began looking for another sport in which to compete at the Olympic level. She turned to triathlon.
Since 1998, Shelly remains a top competitor in triathlon (and duathlon) at the national, regional and local levels. She's also qualified for and has participated in numerous Team USA rosters for the ITU World Championships in both triathlon and duathlon.