While some people absolutely relish riding roller coasters, others can't stand them. Case in point: Jennifer Garner.

The "13 Going on 30" actress uploaded a sidesplitting video to Instagram on Wednesday proving that she is not cut out for the roller coaster life. Unfortunately for her, she had to ride a coaster dubbed Twisted Colossus at Six Flags Magic Mountain because she was filming a scene for her new film, "Yes Day."

For the record, Twisted Colossus stands at 121 feet tall, throws passengers down a 128 foot drop and reaches max speeds of 57 mph.

Garner managed to get her hands on the hysterical footage, narrating the sequence of events that starts with her praying as she overlooks the first drop. She's also gripping her co-star Jenna Ortega's hand for dear life as they dive down the first 80-degree plunge.

"As you can see," explains Garner with a laugh, "I am having a great time." She also sarcastically claims Ortega is the "nervous wreck" and she's the one providing comfort.

The most comical part of the shoot is that Garner is constantly calling her costar by her real name, Jenna, instead of "Katie," her character in the film.

"I don't really believe in being in character," snickers Garner, "I like to live in the moment."

The 47-year-old provides a series of priceless reactions, from panicking as she hurtles toward a complete inversion to shrieking uncontrollably. She also assures that she's "not taking the Lord's name in vain. I am beseeching the lord."

The video abruptly ends as Garner's expression rapidly dissolves from fear, to confusion, to downright incredulity upon the moment she realizes "that the second hill's bigger than the first."