With a posted prize for the winner of "A superb son-in-law" a bunch of middle-aged women turn out for the obstacle course race in this variation on the typical chse comedy of the era.
That means there are camera tricks, men in drag pretending to be the prospective mothers-in-law, and people rolling on the ground and pretending they're falling down a hill. It's one of those movies where the idea seemed irresistibly funny to some one, and they made the film.... and then, because they had, they released it anyway.