Chris Hoy's wife, Sarra Kemp gave birth to Callum 11 weeks early in October 2014 weighing just two pounds two ounces before he spent nearly five months in hospital.
But nine months on, the tot is keeping his dad company in the gym, sitting up for his first time on his own underneath a massive weight.
Not quite in the most suitable gym wear - a denim dungarees and striped long-sleeve top, the proud father tweeted: "Got a new gym buddy to spot for me. @SarraHoy!"
And Hoy's wife confirmed the photo of Callum helping his dad out with weights coincided with the exact same day he managed to sit up for the first time.
After she retweeted the photo of her son helping his dad out in the gym, writing: "Gotta love a boy who coordinates his outfit with his gym equipment", someone tweeted her saying: "Sits up better than our baby - due dates around the same time, ours born at term."
The mother replied: "That’s so kind of you to tweet. Ours just learned to do that today!"
Fans who saw the photo tweeted by the Hoys carried on with the comical angle.
One tweeted: "Very cute. Make sure he doesn't miss leg day! His dad certain never missed that!"
While another wrote: "He looks like he's not impressed with your choice of weights or did you not do enough reps #kidsarehardtaskmasters?"
Callum has come a long way since November last year, when Hoy tweeted a photo of his son in hospital saying he was "doing well".
Thanks for all your messages for Callum. He's doing well so far and says hi! pic.twitter.com/7wXVNybYmU— Chris Hoy (@chrishoy) November 6, 2014