21-year-old fighter dies from rare muscle condition triggered by MMA training, mother vows to spread awareness

A young MMA fighter reportedly passed away after suffering a rare muscle condition that was triggered by intense MMA training. His mother addressed the incident and suggested that she would work toward spreading awareness of the condition to help educate and save others.

Per News.com.au, 21-year-old Australian amateur MMA fighter and physical trainer Jake Sendler passed away due to rhabdomyolysis (aka 'rhabdo'). The rare condition comprises a muscle breakdown where toxins are released into the blood that damage the kidneys. It could also harm other organs. High-intensity exercise, trauma, extreme dehydration, etc., could cause it.

The young athlete aimed to become a professional MMA fighter and PE teacher. Known for his excellent fitness and love for MMA, he trained for and competed in an amateur MMA fight at Road to Hex 3. It took place on March 2, 2025, after which his health deteriorated, and he was admitted to a hospital.

Reports indicated that he underwent multiple surgeries and fought valiantly, but he'd suffered considerable damage. He passed away on March 13, 2025.

Jake's mother, Sharone Sendler, as well as his team at the Mat Masters Academy and the event organizers (Road to Hex) in Australia, expressed their respect for him. Sharone recalled how her son would be full of energy and light up the room, adding that she and their family aim to continue his legacy of helping others.

She implied that they want to raise awareness about the health condition so that no other family has to face what they did. Sharone stated:

"We're going to as a family make sure his legacy lives on. We're going to keep going with his dreams of helping athletes and inspiring youths to be great but also look after themselves because you can't be great if you're not here ... If he could be here, I know he'd be changing lives, so we're going to continue that for him."

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MMA gym pays tribute to Jake Sendler

In addition to working for the noble cause of raising awareness about the health condition, Sharone Sendler underscored the significance of recognizing the symptoms of the condition, as it'd help treat the afflicted person and save them. Per the Cleveland Clinic, some of the symptoms include u*ine that's brown/red/tea-colored, muscle swelling, and possibly even nausea, decreased urination, etc.

Furthermore, a GoFundMe page was set up for the family to raise funds to spread awareness regarding the topic and handle the costs connected with Jake Sendler's passing. The Mat Masters Academy put forth an Instagram post to express their respect for Jake. An excerpt from it read as follows:

"You can honour Jake by raising awareness of this life-threatening condition and supporting his family through donations or by sharing his story. Jake's legacy lives on in the strength and kindness he shared with the world. Your fight continues through us ... #JakeStrong #RhabdoAwareness"

Check out the academy's and the Australian MMA podcast's shared Instagram below: