[1] Cowley competed in the 2013 World Championships in Moscow and the 2016 Summer Olympics in Rio de Janeiro.

[2] For both of his major championship competitions, Cowley qualified in the 20 kilometres race walk.

[3] In 2021, he competed at the 2020 Summer Olympics in Tokyo where he finished in 8th in the men's 50 kilometres walk with a new personal best time of 3:52.01 just 113 seconds behind the eventual winner Dawid Tomala of Poland.

[3][10] He then competed at the 2010 World Junior Championships in Athletics where he finished 17th in the 10 kilometres event.

[3] Cowley has said he was inspired when rival Australian race-walker Jared Tallent was awarded his gold medal for the 50 kilometres walk at the 2012 Summer Olympics in 2016 after Sergey Kirdyapkin was disqualified for doping.

"[2] In 2019, he competed in the men's 20 kilometres walk at the 2019 World Athletics Championships held in Doha, Qatar.