Former NFL star Chris Johnson is opening up about the heartbreaking health battle that has dramatically changed his life, revealing that he has been diagnosed with amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease.

The former Tennessee Titans running back, who dazzled football fans with his record-breaking speed and became the NFL’s Offensive Player of the Year in 2009, shared his diagnosis during an emotional appearance on Good Morning America. Now 40, Johnson communicated through a speech-generating device using his recorded voice after the disease robbed him of his ability to speak.

“There’s no history of ALS in my family,” Johnson said. “My doctors believe my case is what’s called sporadic ALS, which is actually how the vast majority of ALS cases happen.”

“That’s one of the reasons this disease can be so shocking,” he continued. “It can happen to someone who never expected it.”

Johnson said the first warning signs seemed minor. He noticed weakness in his right hand, and his grip wasn’t as strong as it once was. At first, he and his family assumed the symptoms were related to the physical toll of his decade-long football career.

“I thought because of football and, you know, his career, that it had to be something with that,” his wife, Brittany Johnson, told GMA. “Maybe … a pinched nerve or something along those lines, but never ALS.”

Instead, the diagnosis turned their lives upside down.

“Honestly, I don’t know if you ever fully process it,” Johnson admitted. “At first, you’re in shock. Then you realize you have two choices. You can give up, or you can fight. I chose to fight.”

ALS is a progressive neurological disease that causes the brain to lose its ability to communicate with muscles throughout the body. Over time, patients gradually lose the ability to walk, talk, eat, write, swallow, and eventually breathe. There is currently no known cure.

Johnson said the disease has progressed much faster than he expected.

“It’s continued to progress much faster than I ever imagined. I want people to understand just how quickly ALS can attack your body,” he said. “Just over a year ago, I was picking up my 7-year-old daughter so she’d make a wish with her birthday cake. Today, I couldn’t do that.”

Despite the devastating changes, Johnson emphasized that his condition has not changed who he is inside.

“People sometimes look at the physical disability and assume you’re not still the same person inside,” he said. “I still think the same. I still dream. I still love my family. My body just doesn’t cooperate.”

Johnson credits his wife and their four children for giving him the strength to keep moving forward.

“They give me a reason to keep going,” he said.

The Johnson family is also participating in experimental treatments, hoping not only to slow the disease’s progression but also to help researchers develop better options for future ALS patients.

News of Johnson’s diagnosis prompted an outpouring of support across the NFL. The New York Jets, one of his former teams, posted on X: “Our entire Jets family is with you, @ChrisJohnson28. Sending strength and support as you face this challenge.”

Johnson played 10 NFL seasons with the Titans, Jets, and Arizona Cardinals, rushing for 9,651 career yards and 55 touchdowns. His unforgettable 2009 campaign included 2,006 rushing yards and earned him Offensive Player of the Year honors. Today, however, his greatest battle is taking place far from the football field—and his determination to fight continues to inspire many.