Kate Hudson's kids keep her fit

Actress Kate Hudson is struggling to keep up with her "feisty" 14-month-old son Bing and often wears roller skates when she takes him out.

She insists her energetic kid with Muse frontman Matt Bellamy was never truly a toddler because he started running just days after he learned how to walk.

Hudson explains, "He went from taking a couple of steps to sprinting... A couple of days before his year birthday he started walking and then, I guess, two days after that he started (running)."

Her eight-year-old son Ryder's passion for sports only served to encourage the tot to go for it.

The Almost Famous star adds, "Ryder plays a lot of soccer and he just started dribbling a soccer ball and it was like, 'Oh boy, here we go!' So now I have my roller skates on and he's just running and into everything."

Hudson admits her energetic sons keep her fit - Ryder works out with mom and takes kick boxing classes with her.

She explains, "Ryder gets on my back and I'll have to do sprints with him on my back, and squats - and we laugh our butts off."