Gym Goer's Arms 'Exploded' After CrossFit Workout Challenge Gives Her 'Blood Poisoning'

After the rigorous 'Murph Challenge', Jessica Johnson's arms swelled — a symptom of a rare, but potentially lethal, condition

A South Carolina gym enthusiast says her arms “exploded” after she attempted to do a vigorous fitness challenge — which she says caused a life-threatening condition.

Jessica Johnson, 25, had been doing the “Murph Challenge” — a fundraising challenge consisting of running a mile, then doing 300 squats, 200 push-ups and100 pull-ups, before finishing with another one-mile run.

“I was doing 10 sets of five pull-ups,” the Charleston-based healthcare worker said, and was “pretty tired” after her workout, as she told Kennedy News Agency, via the New York Post.

The next day, her arms were swollen and sore, but, “I thought ‘I haven’t done pull-ups in forever, it was a hard workout, they’ll go down, it’s fine,' ” she said.

But instead of her recovering, her arms continued to swell.

“Everyone said, ‘We just thought you were super jacked or something,' ” Johnson told the outlet.

Related: Mom Hospitalized After Drinking a Gallon of Water a Day for '75 Hard' Fitness Challenge

But then, she developed another symptom: “I was drinking tons of water but I wasn’t peeing much during the day,” she said, adding that when she did urinate, “It was darker, almost like an orangery color.”

Johnson said she sought medical care and was promptly referred to the hospital, where blood tests determined she had rhabdomyolysis.

It’s “a rare muscle injury where your muscles break down,” the Cleveland Clinic explains, saying it’s “a life-threatening condition that can happen after an injury or excessive exercise without rest.”

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In rhabdomyolysis — or rhabado — “your muscles break down (disintegrate), which leads to muscle death. When this happens, toxic components of your muscle fibers enter your circulation system and kidneys.”

This can cause kidney damage — and as Johnson said, “In rhabdomyolysis your cells are basically exploding in your muscles.”

“It’s like blood poisoning since your body can’t really filter it out.”

Related: Indiana Mom Dies from Water Toxicity After Drinking Too Much Water

Doctors had to cut her arms to alleviate the swelling — but Johnson says her kidneys managed to survive.

“They kept telling me, ‘We don’t know how you don’t have kidney damage right now,' ” she said.

While she says she’s made a “full recovery,”  Johnson says “This was a wake-up call for me to chill out a bit” — and not just by taking a break from the Murph Challenge, but by pivoting to cardio and “more gentle pilates stuff.”

“Working out too much and doing too aggressive of a workout is not good for you and not healthy.”

There are no other known similar incidents arising from this challenge. PEOPLE has reached out to CrossFit and Forged, which sponsors the Murph Challenge, for comment, and will update with further info.

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