This was a very funny Popeye cartoon, right from the start before anyone said anything. Check out the spelling outside Popeye's gymnasium: "Healt Classes For Wimmen," "Vitaliky Is Personaliky" and Healt Is Wealt." Oddly, he spelled "Gymnasium" correctly. Figure that out!
Bluto, who owns the cabaret next door, sees Olive head into the gym and stops here. "Hey, getting healthy is the bum. Come out with me and have a good time." Olive tells him to scram, so this brute really is jealous of his neighbor, who is getting all the customers while he is getting none.
That sets up the normal conflict between these two rivals once again, except this has a twist. Bluto shaves, puts on a wig and heels and walks into Popeye's women's fitness class. Nobody knows each other in this episode. Olive calls Popeye "professor" as he leads an aerobics class (well, the 1930s version).
Bluto disrupts the class, of course, and....well, I can't say without spoiling things but there are some outstanding sight gags in here and some funny mumbles by Popeye as this overgrown, muscular "woman" is causing havoc and Popeye won't fight back because a gentleman doesn't hit a woman.
Whoever did Bluto's voice deserves accolades but he's not listed here. A guess is that it is Gus Wickie, who did most of the Popeye cartoons in the '30s.