June 29 (UPI) — Former Tennessee Titans star Chris Johnson, one of the fastest running backs in NFL history, was diagnosed with ALS, he announced Monday.

Johnson made the announcement on Good Morning America. The 40-year-old NFL legend said he received the diagnosis in 2025.

“I want people to know that I’m still me,” Johnson said through a speech device. “ALS has changed what my body can do, but it hasn’t changed who I am.”

Johnson, who once used his eyes to find tiny rushing lanes in NFL defenses, now leans on them to operate a keyboard on a device, which produces his voice through a speaker and allows him to communicate.

He said he shared his battle to help others receive earlier detections of ALS, to inspire research and to give hope to families.

Johnson first noticed weakness in his right hand and declining strength, which led him to seek medical guidance. He said doctors first told him to get his “affairs in order,” but he went on to seek experimental treatment. Doctors believe Johnson has sporadic ALS, the most common form of the disease, which surfaces despite no family history of the illness.

Sporadic ALS affects 90 to 95% of those living with the disease, according to the ALS Association.

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

Johnson said his wife, Brittany, and family give him “a reason to keep fighting.”

The three-time Pro Bowl selection, 2009 first-team All-Pro and former Offensive Player of the Year spent six of his 10 NFL seasons with the Titans. He also spent time with the Arizona Cardinals and New York Jets.

His 2,006 rushing yards from the 2009 season with the Titans are the seventh most in NFL history.

“Some people leave a mark on an organization that you just can’t put into words,” Titans owner Amy Adams Strunk said in a statement. “Chris Johnson is one of those people for us. His leadership on the field, in addition to his impact in the locker room and Nashville community have written him permanently into the story of this franchise.

“Learning this news is extremely difficult, and we will support Chris every step of the way throughout his journey. We are holding him and his family close, and join our fans around the world in expressing our love for Chris.”