A “cross-trainer” (elliptical trainer) is not the same thing as a “trainer who is cross,” but there are jokes. This was posted on Twitter by Bob Kostic on January 10, 2018:

“I bought an exercise machine, but when I assembled it, a message kept flashing up and saying, ‘Get the fuck off me’. I took it back and told the assistant what was happening. He said, ‘Well, it is a cross trainer.’”


Wikipedia: Elliptical trainer
An elliptical trainer or cross-trainer (also called an X-trainer) is a stationary exercise machine used to stair climb, walk, or run without causing excessive pressure to the joints, hence decreasing the risk of impact injuries. For this reason, people with some injuries can use an elliptical to stay fit, as the low impact affects them little. Elliptical trainers offer a non-impact cardiovascular workout that can vary from light to high intensity based on the speed of the exercise and the resistance preference set by the user.

Twitter
Bob Kostic
@causticbob
I bought an exercise machine, but when I assembled it, a message kept flashing up and saying, “Get the fuck off me”. I took it back and told the assistant what was happening. He said, “Well, it is a cross trainer.”
5:17 PM · Jan 10, 2018·Twitter Web Client

Twitter
Jokes UK
@jokesuk
I bought an exercise machine, but when I assembled it, a message kept flashing up and saying, “Get the fuck off me”.
I took it back and told the assistant what was happening.
He said, “Well, it is a cross trainer!”
12:59 PM · Jan 10, 2019·Twitter for iPhone

Twitter
Short Bloke Josh!
@ShortBlokeJosh
I bought a flashy new exercise machine yesterday, but when I assembled it, a message kept flashing up & saying, “Get the f#%k off me!”.
I took it back & told the assistant what was happening.
He simply replied, “Well, it is a cross trainer!”
#JoshJoke
#Puntastic
4:49 PM · Jan 10, 2019·Facebook

Twitter
Bob Kostic
@causticbob
I bought an exercise machine, but when I assembled it, a message kept flashing up and saying, “Get the fuck off me”.
I took it back and told the assistant what was happening. He said, “Well, it is a cross trainer.”
9:24 AM · Jan 10, 2021·Twitter Web App

Twitter
GrahamGeog
@GrahamGeog
I bought @ScottPughsley an exercise machine as part of his new Joe Wicks regime. When he stood on it, a message flashed up saying ‘GET THE HELL OFF ME’.
I took it back to the shop and asked the assistant what was happening. He said, “Well, it is a cross trainer innit!” Rolling on the floor laughing LOL Face throwing a kiss
GIF
12:31 AM · Jan 11, 2021·Twitter for iPhone