Former NFL running back Chris Johnson has revealed that he is battling ALS, sharing his diagnosis publicly for the first time during an emotional interview on ABC's Good Morning America. Matt Sulivan Getty Images Johnson, 39, said he was diagnosed with amyotrophic lateral sclerosis (ALS) in 2025 after first noticing weakness in his right hand. Doctors determined he has sporadic ALS, the most common form of the disease, meaning it developed without any family history. The dise