After retiring from gymnastics in 2010, he continued to play lacrosse for a team in Vermont while he was studying in Montreal.

[citation needed] In 2016, Vellner earned his first CrossFit Games invite after finishing 8th in the World (1st in Canada) in the Worldwide Open and 3rd in the East Regional.

[11][12] After the Games, Vellner competed on Team Canada at the CrossFit Invitational, earning a 4th-place finish alongside Michele Letendre, Carol-Ann Reason-Thibault, and Brent Fikowski.

Although Vellner narrowly missed qualifying for the Games at the Open, his 1st place finish at Wodapalooza earned him a spot in the competition.

[22] However, a quirk in the scoring system meant that despite finishing 1st in the world, he was not crowned the Canadian National Champion.

[citation needed] He then compete at the Dubai CrossFit Championship, earning 2nd,[23] repeat as the Wodapalooza Champion,[24] and take home 1st in the Rogue Invitational,[25] which moved online in response to the COVID-19 pandemic.

Vellner finished 20th in the World and 13th in North America in the Worldwide Open, earning a spot in the Online Quarterfinal.