When he was in eighth grade, he broke his arm while armwrestling his father's friend, and has stated that this breakage increased his tendon strength significantly.

[12] He also had an uncredited cameo in the 1987 Sylvester Stallone film Over the Top, and was the subject of the feature documentary "Pulling John", directed by Vassiliki Khonsari and Sevan Matossian.

The documentary chronicles Brzenk's legendary arm wrestling career by following him intimately for 4 years, in which John competes in global tournaments and ponders retiring from the sport he loves.

[13][14] After defeating Marcio Barboza in the 2015 WAL Heavyweight Right-Handed Championship, Brzenk would take an extended period of time off from armwrestling due to injuries.

[17] On December 11 of the same year, John Brzenk would face right-handed heavyweight title holder Devon Larratt at King Of The Table 2 (KOTT 2).

[21] On November 19 of the same year, in the next installment of East vs West, Brzenk would defeat Oleg Petrenko in a right-handed supermatch in dominant fashion, 3–0.

[22] On January 21, 2023, John Brzenk would participate in a fifth consecutive installment of East vs West, losing a hard-fought supermatch to Irakli Zirakashvili by a score of 3–2.