Diagnosed with ALS in 2011, former NFL player Steve Gleason agreed to let filmmaker Clay Tweel document his battle with the disease, partly so his newborn son would have a record of him before he lost the ability to speak. “This is not gonna crush my life, even if it crushes my body,” Gleason insists, and the early scenes show a man of exceptional candor, eloquence, and determination. He embraces fatherhood, tries to mend fences with his own emotionally detached dad, and spends his last precious days of motor activity launching a foundation to help other ALS patients. But as Gleason’s physical condition worsens, the documentary becomes a harrowing study in marital devotion, capturing him and his loyal wife, Michel Varisco, in a series of increasingly bleak moments together. “What can I do to be more important to you?” Gleason asks her piteously, but one already knows the answer: nothing.