Physical Fitness jokes

What was Frankenstein's second job? -- He was a bodybuilder.

A lady weightlifter goes to the doctor and says, "Doctor, I have a confession." The doctor asks, "What is that?" She replies, "I've been using steroids and....I think I've grown a penis." The doctor looks at her and asks, "Anabolic?" There's an awkward silence then she replies, "No, just a penis."

What's the difference between me and Spongebob?

Spongebob can actually get ripped.