Stranded NASA astronauts on ISS have to carry out this brutal regime every day to avoid serious health issue

The case of stranded NASA astronauts Sunita "Suni" Williams and Barry "Butch" Wilmore has gripped the nation.

Even President Donald Trump calling on Elon Musk to try and get them back sooner than expected with his SpaceX rockets, their eventual return is set to be quite the event.

NASA has already explained why it's not as simple as Musk flying up there to rescue Williams and Wilmore from the International Space Station, although they’re supposed to be back on Earth sooner than expected thanks to their return being moved up.

After flying to the ISS as part of 2024's first crewed mission of the Boeing Starliner, Williams and Wilmore were given an extended stay due to issues with their craft. It was flown back unmanned, leaving them trapped there until SpaceX's Crew 9 mission can pick them up with its spare seats.

Williams previously said she was losing basic human functions, but to combat that, she and Wilmore have to undergo a 'brutal' daily regime to ensure they're fighting fit when back on Terra Firma.

Explaining some of the unexpected side effects to students at Needham High School in Massachusetts (via Mail Online), the 59-year-old astronaut admitted: "I've been up here long enough, right now I've been trying to remember what it's like to walk. I haven't walked. I haven't sat down. I haven't laid down."

Speaking during a January 31 press conference, she expanded on the daily routine that is supposed to avoid excess bone density loss. NASA has revealed that astronauts will typically lose 1% to 2% of bone density in the hip and spine for every month they're in space. The site writes that this is "compared to bone loss of 0.5% to 1% per year in post-menopausal women and much older men on Earth."

With a loss of bone density, Williams and Willmore's bones would be more fragile and susceptible to an increased risk of breaks alongside 'early-onset osteoporosis'.

Williams’ daily routine involves her taking part in up to two hours of exercise a day.

Seeing the positives, she added: "Your joints don't hurt, which is quite nice."

While hitting the intergalactic gym, Williams and other astronauts complete variations of treadmill running, stationary biking, and resistance strength training.

Although there were already concerns about Williams' appearance, NASA has reiterated they're given regular medicals to ensure they're doing well while aboard the ISS.

In a statement to Mail Online, NASA promised: "Suni Williams is successfully performing all duties and functions during her mission aboard the International Space Station, including her daily exercise routine, spacewalks outside of the space station, and a variety of science experiments inside the orbiting laboratory."

While Williams has said she can't wait to get home and eat a pizza, at least she’s finding the brighter side of being stuck in space.

On January 30, she posted the ultimate selfie as she serviced the ISS during a spacewalk. Not everyone can say they've snapped a selfie while flying 423 km above the Pacific Ocean