[3] After graduating from high school in 1988, Gruenwald attended the Maranatha Baptist University in Watertown, Wisconsin, where he trained and competed for the wrestling team coached by 1972 Olympic champion Ben Peterson.

[9][10] After his first Olympics, Gruenwald proved particularly successful in his career with two U.S. national titles (2003 and 2004) and obtained a World Cup series trophy in 2002, reaching into the top spot for his weight class in the wrestling team.

He also reeled off three-straight top-ten finishes at the World Championships, and then captured a bronze medal in the 60-kg class at the 2003 Pan American Games in Santo Domingo, Dominican Republic.

He withdrew from the bronze medal match against Romania's Eusebiu Diaconu with a shoulder injury, after losing to Bulgarian wrestler and double Olympic champion Armen Nazaryan in an astounding semifinal bout.

[12][13] Gruenwald pinned Portugal's Hugo Passos with only nineteen seconds left in his opening match, but fell behind Romania's Eusebiu Diaconu by a 3–1 decision to close the pool round.

[2] Gruenwald currently resides in Wheaton, Illinois with his wife Rachel and their seven children: son Adin and six daughters Arwyn, Ava, Autumn, Aleyse, Ashley, and Amber.