Shahlaei started strongman training in 2005 and entered his first novice competition that year, where he finished 8th. Within two years, he entered his first
Britain's Strongest Man, having won the Midlands qualifier. In that competition in 2007, he made a huge impact, making it to the final only to tear his biceps in the tyre flip, which forced him to withdraw. He won the Midlands qualifier again in 2008, and once again made the final, this time finishing 4th behind
Jimmy Marku,
Terry Hollands and
Mark Felix. This placing landed him an invite to the
World's Strongest Man in 2008, however he did not make the finals. In 2009, four years after beginning strongman, he became the
UKSC Midlands Strongest Man and also won the UKSC
England's Strongest Man. Shahlaei did not compete in the WSM qualifier titled England's Strongest Man, which replaced the Britain's Strongest Man contest in 2009 and was won by Terry Hollands. In 2011
Strongman Champions League Holland, he was equal on points with
Ervin Katona but emerged victorious on count-back. Shahlaei emerged runner-up to
Krzysztof Radzikowski at 2012 WSF Championships in
Abu Dhabi and second runner-up to
Žydrūnas Savickas and
Vytautas Lalas at the 2012
Europe's Strongest Man, but injured his shoulder during 2012 SCL China. He won 2013 Britain's Strongest Man however 3 weeks later, during 2013 World's Strongest Man group stages, he tore his quad during the squat event. In 2014, Shahlaei emerged runner-up to
Hafþór Júlíus Björnsson at the 2014 Battle of the North in
Tórshavn,
Faroe Islands. He suffered a severe injury attempting a personal best deadlift at the
World Deadlift Championships in conjunction with the
2014 Europe's Strongest Man, tearing his lat, forcing him to withdraw from the competition despite sharing third place with
Martin Wildauer with a lift. In 2015 World's Strongest Man group stages, he again sustained an injury during the Norse Hammers event where the second of the three hammers tore his triceps and dropped him to the floor. In his career spanning over 12 years, Shahlaei competed in 58 international competitions and won 8 of them including his best win, the 2016
Europe's Strongest Man. He also managed to win 4th place at the 2011
World's Strongest Man while securing 7th, 9th, 9th and 10th places in 2017, 2009, 2014 and 2016 respectively, making it five times into the finals. He also competed in the inaugural
World's Ultimate Strongman in 2018 and placed 5th in a stacked field of 12. He also placed 7th in the 2012
Arnold Strongman Classic, widely considered the heaviest and most difficult strongman competition in the world. During 2019 World's Strongest Man group stages, Shahlaei sustained a career ending injury when he tore his
Achilles tendon while performing the super yoke. He made a brief comeback two years later to his final competition 2021 Giants Live Strongman Classic where he won 7th place. ==Other work==