You can’t judge every book by its cover. But we’re going to in the case of the following 10 exercise guides. Judging by their covers, these are some weird workout books.

You can never overtrain at relaxercise.



Adults Only. This unfortunately titled 1980 book is from the guys who brought us the book Pumping Iron. George Butler also co-directed the movie Pumping Iron.






How to do PAWsitive reps with PURRfect form.
Here it is: the most ’80s book ever.



Jack Garbarino: inventor of the home workout.



Let’s get physical.



Do you take the blue steroid pill or the red steroid pill?



This is advanced relaxercise.



With exercises like “The Fantastic One-Two-Three-Four” and Spiderman’s “Way-out Wall Climbs,” this 1976 paperback was purposely weird, and we approve.
“I promise, lady, it’s a bioenergetic exercise.”
See also: Bad Muscle Magazine Covers, Vol. 4 and Joe Weider Sex & Dating Manuals