Pokémon (1997): A Lean Mean Team Rocket Machine!

On their way to Celestic Town, Ash and his friends have to take Piplup to the Pokémon Center after it collapsed from over-excessive training. Meanwhile, Team Rocket, who were following the group on a slope, decide to have lunch in a luxury restaurant. But then Jessie notices that Meowth's golden charm is buried under rolls of flab. The trio now realizes that, due to them having led a rich and luxurious life ever since they had earned the money at the summer school, they have become lazy and grown a lot in flesh. Wanting to return to their former "sharp and cool" shapes, they start a harsh training session.