Plif and Plops have gone fat from far too much food and are so immobile, that Plum-my is really worried about them. He turns into a pair of scales and encourages them both to check on their weight. The result is rather „heavy", and Plummy gives them good advice to do some sports. But these two fat guys are far too sluggish and lazy to do any kind of exercises. But finally, after Plummy turned himself into a basketball-basket and challenges them for a game, they get to like sports and loose the surplus fat rather fast...