A Ballet Bodies student plummeted to the ground when her instructor fell asleep on the job ... according to the woman, who also happened to be 65 years old at the time!
The senior citizen is suing the popular Hollywood workout joint for the incident, and in the suit she says the instructor made her attempt an advanced Pilates exercise called an inverted hanging pike. As you might imagine ... it didn't end well.
The woman says her instructor failed to spot her and she ended up falling more than 6 feet onto the hardwood floor -- directly on her head.
She says she suffered whiplash, a concussion and a cervical strain and continues to battle numerous nagging pains and headaches.
The inverted hanging pike is no joke, btw. Imagine your grandma in this position.