Here's an aerobics class being given at the Women's Building in San Francisco's Mission District in 1979. 

Begins with a high-angled shot of a group of women wearing spandex leotards and leggings and following the movement of an aerobics instructor. They shrug their shoulders, bounce to the rhythms of the music playing, roll their shoulders back, do several pirouettes, and more.

Next we see the group of women from behind the class, looking towards the instructor. Spotlights shine into the camera.

Then we see a group of women from the side, sitting on the floor with their arms extended. They look upward to the ceiling of the room as if to stretch their neck muscles.

The clip ends with a focus on the instructor who has the women doing more slow pirouettes with their arms and legs extended.