What is ALS? Former Tennessee Titans RB Chris Johnson reveals shocking diagnosis and progression via Good Morning America interview (Image via Getty: Chris Johnson)Tennessee Titans legend Chris Johnson revealed his ALS diagnosis in a Monday interview on Good Morning America. The 40-year-old former running back said there is no history of ALS in his family. “My doctors believe my case is what’s called sporadic ALS,” the three-time Pro Bowler said. “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.” Tennessee Titans legend Chris Johnson reveals shocking ALS diagnosis via Good Morning AmericaThe diagnosis came as a surprise to Chris Johnson and his wife, Brittany Johnson. “Honestly, I don’t know if you ever fully process it. 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.” Talking about the progression of the disease, 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.” His disease has progressed quickly. And now, he uses a speech-generating device to talk.Tennessee Titans owner Amy Adams Strunk releases a statement for Chris JohnsonThe statement shared on the official X account of the Tennessee Titans read:“Some people leave a mark on an organization that you just can’t put into words. 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.”What is ALS?According to Mayo Clinic, ALS is short for Amyotrophic Lateral Sclerosis. ALS is often called Lou Gehrig’s disease.It is a nervous system disease that affects nerve cells in the brain and spinal cord. Symptoms include muscle twitching, muscle weakness in an arm or leg, trouble swallowing, or slurred speech. Eventually, it affects the muscles required for moving, speaking, eating, and breathing. There is no cure for this fatal disease. Research into new therapies is ongoing. According to The ALS Association, ALS is caused by the death of motor neurons [a type of cell in the central nervous system that coordinates movement]. When motor neurons die, they cannot communicate or connect with muscles. This leads to muscle atrophy, weakness, and eventually paralysis. A 2017 study in people with ALS, with or without head injury, showed that “head injury was not associated with faster ALS disease progression,” and did not result in a specific pathology in the brain. In Match 2017, former San Francisco 49ers wide receiver Dwight Clark announced he was diagnosed with ALS. He passed away a year later in June 2018 at the age of 61.Other notable NFL players who have been diagnosed with ALS include former New Orleans Saints defensive back Steve Gleason, former Tennessee Titans linebacker Tim Shaw, former Baltimore Ravens linebacker O.J. Brigance, former New England Patriots fullback Kevin Turner, and former Atlanta Falcons linebacker Tim Green. Tim Green runs a podcast despite an ALS diagnosisIn 2018, CBS News’ Steve Kroft asked Tim Green if there was any connection between playing football and his ALS. “I think probably a lot, if not all,” the former Falcons linebacker said then. Tim Green uses his AI-generated voice, created by ElevenLabs, to host the Nothing Left Unsaid podcast with his son, Troy Green.The former Falcons star refuses to let ALS silence him. The podcast creates a lasting legacy for him, even when he has lost his original voice.