Why RFK JR just posted video hopping into an ice bath wearing jeans

US Health Secretary Robert F. Kennedy Jr has gone viral for plunging into an ice bath with his jeans on - yes, this is a real sentence.

The 72-year-old shared a bizarre one-minute and thirty-second-long video on social media yesterday with controversial musician Kid Rock, 55, in an effort to inspire Americans to work out.

He penned in the caption: "I’ve teamed up with @KidRock to deliver two simple messages to the American people: GET ACTIVE + EAT REAL FOOD."

In the questionable video, the two men do a series of workouts together in the gym before taking off their shirts.

One particularly strange moment sees Kennedy and Kid Rock in a sauna, with the former pedalling on an exercise bike while the latter does push-ups in the background, before they swap.

Then, things get even weirder as the Health Secretary keeps his denim jeans on to get into an ice bath.

"Where's Kid?" he asks as he goes looking for his pal, while the camera pans to the musician relaxing in a hot tub.

They also enjoy a dip in the pool and then play a game of pickleball.

Elsewhere in the video, Kennedy downs a glass of whole milk, poses with an American flag, and eats a large cut of steak, before 'Make America Healthy Again' flashes across the screen in reference to his campaign.

Strangely, it's not the first time the politician's infamous jeans have been in the spotlight, and the amount he wears them, during even the most brutal exercise, has become a joke in itself.

In July, he embarked on a hike in Phoenix, Arizona, when it was 41°C, in, you guessed it, his trusty denim jeans.

Kennedy's also been pictured in a number of other places, including the gym and playing with his grandchildren in a muddy creek, shirtless, but sporting his jeans.

As for the milk moment, US President Donald Trump signed legislation in January allowing schools to serve students whole milk, so this part of the clip was a nod to that.

Reacting to the new video, which has been seen a whopping 9.7 million times, one X user penned: "Does anyone find it strange that he wore jeans into the bath?"

While a second asked: "Why does RFK jr only work out in jeans?"

And a third theorised: "Pants in a tub mean you likely have extremely problematic tattoos on your legs."

"Has anyone seen the Secretary of HHS? Oh sure, he’s in Kid Rock’s indoor pool chugging whole milk in his jeans creating content for social media," sarcastically quipped a third.

A fourth wrote: "This jeans in the gym/tub/pool/sauna/everywhere thing is getting to be a bit much."

Meanwhile, someone else chimed in with: "Him doing all of this in jeans is wild".

Kennedy previously addressed his fashion choices in a TV interview with Fox News back in August, explaining: "Well, I just started doing that a long time ago because I would go hiking in the morning and then I’d go straight to the gym. And I found it was convenient, and now I’m used to it, so I just do it."