Chris Johnson, a former running back for the Tennessee Titans and Arizona Cardinals, disclosed in an interview with ABC's "Good Morning America" that he has been diagnosed with ALS. This interview was broadcast on Monday.Former NFL player Chris Johnson reveals ALS diagnosis at 39, discussing symptoms and impact. (AP Photo/Lynne Sladky)Chris Johnson's ALS diagnosisJohnson, 39, informed GMA co-anchor Michael Strahan that he received his diagnosis in 2025. Amyotrophic lateral sclerosis (ALS), previously referred to as Lou Gehrig's disease, is a neurological condition that impacts motor neurons. Motor neurons are the nerve cells located in the brain and spinal cord responsible for regulating voluntary muscle movements and respiration. There is currently no known cure for the disease.Also Read: What is Aryna Sabalenka and Georgios Frangulis combined net worth? All on her fiancé, wealth and huge engagement ring“There's no history of ALS in my family,” said Johnson while using a speech-generating device that operated on recordings of his own voice to communicate. "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. It can happen to someone who never expected it."Chris Johnson's career: Who is he?Johnson participated in 10 seasons in the NFL, playing for the Titans from 2008 to 2013, the New York Jets in 2014, and the Cardinals from 2015 to 2017. He acquired the nickname CJ2K after achieving 2,006 rushing yards in 2009, a record that still stands as the seventh highest in NFL history. That season, he also set the NFL single-season record for total yards from scrimmage with 2,509 yards and was honored as The Associated Press NFL Offensive Player of the Year.Titans owner Amy Adams Strunk issued a statement regarding Johnson's diagnosis, emphasizing that the former running back's "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." Strunk affirmed that the Titans would provide support to Johnson throughout his journey.The Jets also expressed their support for Johnson.Chris Johnson to participate in clinical trialJohnson, who is participating in a clinical trial as part of his treatment, informed Strahan that he initially began to notice symptoms when he experienced a diminished grip strength.Speaking to Strahan, his wife Brittany said, "I thought because of football and, you know, his career, that it had to be something with that. Maybe ... a pinched nerve or something along those lines, but never ALS."“It's continued to progress much faster than I ever imagined. I want people to understand just how quickly ALS can attack your body. 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,” Johnson said.Johnson stated that he is disclosing his diagnosis to increase awareness, while also informing others that he remains the same individual he was during his NFL career.