Particularly known for his impressive pressing ability and prowess in various stone and moving events, Kieliszkowski is the current world record holder of the Cyr dumbbell press for maximum weight,[4] the 400 kg (882 lb) timber carry farmer's walk (raw grip) for time,[5] the 450 kg (992 lb) car walk for time,[6] the Odd Haugen tombstone to shoulder for reps,[7] and replica Steinstossen strongman events.

In 2018, Kieliszkowski would podium for the first time at World's Strongest Man, finishing 2nd behind Hafþór Júlíus Björnsson.

In March 2020, despite winning four events, Kieliszkowski would finish 2nd at the Arnold Strongman Classic to defending champion Hafþór Júlíus Björnsson.

In March 2023, Kieliszkowski returned to the Arnold Strongman Classic competition after a 3-year absence and finished 2nd to Mitchell Hooper.

[20] Kieliszkowski returned in November and won the Magnús Ver Magnússon Strongman Classic in Iceland.