Peter Andre has been forced to defend his 11-year-old son’s weightlifting after a video he shared of his children at a gym attracted criticism.

In the clip, Junior, who is the son of former glamour model Katie Price, was bench-pressing while his sisters, Princess, nine, and Amelia, three, were skipping and hiding at a gym.

While many were supportive of the family promoting an active lifestyle, others told the former popstar his children “should be running around outside not in a gym”.

“Don’t really think the gym is the place for an 11-year-old,” wrote another follower.

Addressing the backlash he received after posting the clip to Instagram last week, the 44-year-old said Junior was lifting a “featherweight”.

Peter Andre and Katie Price. Image: Getty

The father-of-four described his children's trip to the gym as "a bit of fun" in a column he wrote for New! magazine , adding that he "was there with (Junior) the whole time".

"I wouldn't let him lift anything heavy! I was in the gym at 11, 12 years too," he told his readers.

"We like keeping fit together - it's just a bit of fun. Relax, people!"

Listen: Is crossfit for kids safe? (Post continues after audio.)

Fans also defended Andre's parenting, with one commenting, "The weights are tiny and it's just a father enjoying time with his children messing around in the gym it's not a serious hardcore session."

"It's good that they are being taught to use the gym safely and properly under their dad's guidance - as long as they don't grow up completely paranoid about having 'perfect' bodies!" cautioned another.

Andre and Price are parents to Junior and Princess, while Andre raises Amelia and five-month-old Theo with his second wife Emily MacDonagh.

Price is also mum to 14-year-old Harvey, three-year-old Jett and two-year-old Bunny.