After assigning contestants the task of constructing a bridge, Hamish and Brickman (Ryan McNaught) then went around testing how much each one could endure.
The pair then proceeded to lift the weights onto each Lego structure.
Fans of the show were quick to take to social media to mock the dad of two.
'Hamish looks like he is struggling more with the weight (16kgs) than the bridges,' tweeted one fan.
'Hamish please don't hurt yourself with those weights lol,' tweeted another.
Even Hamish himself was happy to mock his struggle, after running out of kettlebells to pile onto one particularly sturdy bridge.
'It was looking likely at this stage that we were going to have to go to my car and get some of my 600 or 700-kilo kettle bells,' he joked, before cheekily adding: 'That I just have in case I need to do a quick workout.'