Kristen Bell reveals 'dangerous' morning routine: 'Absolutely brutal'

Actress Kristen Bell has revealed her "absolutely brutal" morning routine in an effort to improve her mood.

The Forgetting Sarah Marshall star posted a video on Instagram of her walking outside in a plunging one-piece towards her pool on a winter morning.

She revealed to her followers she was trying out a cold plunge, which involves immersing your body in cold water for at least a minute.

The trend, made famous by extreme athlete Wim Hof and embraced by a number of celebrities, including Chris Hemsworth and Lady Gaga, is said to help balance hormones, improve sleep and produce endorphins.

"Experimenting on myself to find the benefits of cold plunging," Kristen said in the caption on her video.

"It’s also said to not only improve your mental state at the moment but also helps with mental acuity and alertness throughout the day. BRING IT ON."

In the video, Kristen gets into her backyard pool and reveals the temperature is just 14C.

"It's brutal," she said.

The actress then shared a couple of tricks she said had helped her prepare herself for the cold temperatures.

"Number one. Don't stop when you walk into the pool because if you stop, you'll never get in," she warned.

"Number two. Breathe from your belly because otherwise you'll just breathe from up here," she added, pointing to her shoulders.

"It's awful."

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Her third tip encouraged people trying the plunge to count 20 seconds and wait for "a tiny bubble to form around your body and it's like your own personal wetsuit".

"And then you just wait it out."

She added it helped to put a song on that pumped you up so you could disassociate from what your body was experiencing.

"It's absolutely brutal, but you know that no part of your day will be as awful as that. So that's how you can tell it's gonna be a good one," she ended the video.

Fans and celebrity pals praised the star for giving the "brave" morning routine a go.

"You're brave! Never heard the count to 20 tip but will try it!!!" one said.

"Just started doing cold showers and it’s so life-changing," another commented.

"So so good for nervous system regulation! And a cold plunge is a great way to help you when you feel overwhelmed and dysregulated!!" a third added.

The American Heart Association has warned however cold plunges and ice baths can come with some risks.

"That cold shock can be dangerous," director of preventive cardiology at Boston's Brigham and Women's Hospital, Dr Jorge Plutzky, said in an article for the health organisation's website.

"Whether there are health benefits or not is not clear and has not been established."

The association added that submerging your body in cold water could trigger a rapid increase in breathing, blood pressure and heart rate, which could cause a person to drown if they involuntarily gasped underwater as a result. It warns the practice also places stress on the heart, forcing the organ to work harder.

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