When Stephanie arrives in LazyTown, to spend the summer with her Uncle Milford, she finds that she has trouble making friends because all the local kids spend all their time indoors playing video games. So, her uncle enlists the help of Sportacus, an athletic hero who encourages the kids to have fun by remaining active. Unfortunately, this doesn't sit well with Robbie Rotten, a lazy cheat, who takes pride in having LazyTown be the laziest town around, so he plots to get rid of Sportacus.

A day in the life of Sportacus as he goes about his daily routine as a superhero, performing incredible stunts and saving all the residents of LazyTown including Robbie.

Sportacus and the kids help Mayor Meanswell become a secret agent so that he can find out how Robbie Rotten won a race to become mayor of LazyTown.

Robbie tricks the kids into going on a treasure hunt for the LazyTown Stone and then tries to steal it from them until Sportacus arrives to stop Robbie, much like a mysterious hero once stopped the famed Rottenbeard.

Sportacus tries on a new pair of shoes, unaware that they are actually radio-controlled boots that Robbie will use to ruin Sportacus' athletic skills during Spectacular Sports Day.

Ziggy tosses out a toothbrush, a birthday gift from Sportacus, in favor of a taffy machine from Robbie Rotten. Soon, Ziggy is unable to stop the gadget when it begins to get out of control and covers LazyTown in taffy.

The kids decide to grow fruits and vegetables for a Sports Candy Festival for Sportacus. However, Robbie wants them to stop eating healthy foods and ruin the festival, so he disguises himself as life-size fruits and vegetables, hoping to scare the kids and stop the festivities.

The kids join the Lazy Scouts, led by Scoutmaster Robbie, who promises to teach them the easy and lazy way to go camping. This doesn't sit well with Stephanie, especially when she discovers that the kids are ill-prepared for an oncoming storm.

Robbie uses a device to erase Sportacus' memory.

Robbie uses a soccer-playing robot to play against Sportacus in a game.

Stephanie and Ziggy go around LazyTown asking everyone what are their favorite LazyTown songs.

Robbie causes panic in LazyTown when he disguises himself as Dr. Rottenstein and makes everyone believe that vegetables are at the root of a new disease.

A missing page from Stephanie's diary causes trouble amongst the kids.

Everyone in town is busy trying to set new world's records, with Robbie trying to make LazyTown the World's Laziest Town.

Pixel creates a remote that controls everything.

A dance competition is underway in LazyTown. Robbie believes that if Stephanie wins, LazyTown will become too active, so he creates a clockwork dancing girl to compete against her.

Stephanie and Stingy campout with a scared Ziggy who thinks he's seeing a dinosaur roaming about.

The kids enter a treehouse building contest, but find it difficult working with Stingy because he doesn't know how to work as a team.

Pixel invents a machine that makes things vanish, and Robbie tries to get his hands on it so that he can get rid of Sportacus.

Ziggy tries to be a hero just like Sportacus, but his antics start getting him in trouble when he messes up the construction of the kids' new clubhouse.

The kids must face Robbie Rotten in a sports competition without the help of Sportacus after the villain causes the athletic hero to suffer a Sugar Meltdown brought on by a candy apple.

The kids are compelled to do whatever Robbie says and not question him when he disguises himself as Sportacus and gets them to act lazy.

Sportacus takes a holiday and leaves LazyTown in the hands of his good friend Stephanie. As SportaStephanie, she faces her first big challenge when Robbie unleashes a hero-hating machine called Robo-Dog.

Mayor Meanswell is once again getting ready to present the Person of the Year trophy to Sportacus, but can't seem to keep it a secret that Sportacus is the winner. When he hears that Sportacus is winning again, Robbie decides to put a stop to it. Considering the past failures of his evil plans, he decides to hit Sportacus with several of his past failures, hoping that they'll combine into a success.

Bessie's birthday cake turns up missing, and Robbie tricks everyone into believing that Sportacus stole it. The accusations land Sportacus in jail, so the kids get together to prove that he's innocent.