Movies
Did you see the dumbbells this guy lifts? If I lifted dumbbells like those, I would get a hernia the size of the San Andreas Fault.
— Larry • Manhattan Murder Mystery

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The speaker imagines an injury of absurd size if they tried lifting someone else's dumbbells. Comparing a hernia with a vast fault line turns the prospect into comic exaggeration. The joke directs attention toward the speaker's supposed inability to manage the weights.
Context reviewed