The McFly star, 31, showed fans his strength after filming himself doing a series of press-ups...with Buzz on his back.
The two-year-old laid as still as a log as Tom performed his 'Dad Workout' in front of the camera. He managed 17 press-ups before uploading the clip to Instagram.
Captioning the footage, Tom said: "The Dad Workout. He's heavier than he looks!"
Tom and his author wife Giovanna welcomed Buzz into the world in March 2014. They also have another son, Buddy, who was born on 16 February 2016.
The couple are famed for documenting their parenting in their Dear Carrie YouTube vlogs, which are predominately to keep Tom's sister Carrie up to date with their antics.
Meanwhile, Tom has recently published his own novel, The Christmasauras. Last month, Tom revealed the book is now set to be made into an animated film.
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