Jack has enjoyed success in both trampoline and double mini tramp events at international competition. After working his way through the junior ranks this experience culminated in a 5th place in the DMT finals at the 2010 World Championships - Metz, France.
Coming back from injury in early 2011, Jack was named onto the Australian team to compete at the China World Cup, where he showed the best result of the Australian men.
Most recently Jack won a bronze medal at the 2014 Australian Gymnastics Championships in Trampoline, and gold in the Sychronised Trampoline competition.
Jack was also selected for the 5th Loulé World Cup and FIG Minsk World Cup 2014 team and the 2014 World Trampoline and Tumbling Championships teams.
In 2015, Penny again competed at Nationals, this time coming fifth in the Trampoline final. He also was selected for the 2015 World Championships placing 40th in Trampoline.
2016 showed a quiet year for Jack focusing on his routines but he has returned in 2017 and is hoping to be selected to represent Australia at his fourth World Championships later this year in Bulgaria.