Tom Cruise is famous enough for running in films that it’s sparked memes, YouTube supercuts, and a good-natured embrace from the actor himself on social media. Until one watches Still: A Michael J. Fox Movie, though, it might not have registered just how much the Canadian-born actor of its title, beloved for his work in the Back to the Future trilogy, is perhaps an even more fitting exemplar of constant motion.

“As a kid, I lacked the faith required to be still,” says Fox, sharing an amusing anecdote of running out of his house and down to the corner store when he was only two years old. Part of the wonder of director Davis Guggenheim’s documentary, a world premiere at the 2023 Sundance Film Festival set for release via Apple TV+ later this year, is the manner in which it compares and contrasts this inherent restlessness with the current realities of Fox’s medical condition.

The movie connects the personal with the professional, interweaving and interrogating various elements in the already well-known life of its subject. The result, buoyed by a superlative, enriching technical package, is an elevated, stirring tale of unbowed hopefulness and continued engagement with the world at large, despite grappling with the debilitating effects of an incurable disease.

Born in Edmonton, Alberta, in 1961, Fox moved to Los Angeles when he was only 18. After grinding it out for a couple of years, he rocketed to fame in the mid-1980s by way of the hit sitcom Family Ties and science-fiction comedy Back to the Future, the latter of which he replaced Eric Stoltz on after filming had already commenced. For three months, Fox would spend 20-hour days shooting both projects concurrently.

Four Golden Globe nominations (and one win) for his work in Family Ties would follow, alongside two hugely successful Back to the Future sequels, plus other big-screen hits such as Teen Wolf and The Secret of My Success. With his boyish looks, crackerjack comedic timing, and off-the-charts likability, Fox seemed poised to become a worldwide star for decades to come.

Then, a curveball from real life. Though he wouldn’t disclose it until seven years later, Fox was initially diagnosed with Parkinson’s Disease when he was only 29 years old, while shooting Doc Hollywood in 1991. Still recreates the first onset of limb and finger trembling, after a night of drinking, which Fox calls “a message from the future.”

Asked why now is the time to tell his story, the 61-year-old performer says, “I love my mind and I love the places it takes me. I don’t want that to get cut short.” To that end, Still leans into new interviews, while also smartly using material from two books by Fox to help provide thoughtful voiceover narration (even showing footage of Fox recording the audiobook versions of the text).

In the film, Fox is candid about his brief, depression-fueled descent into alcoholism (he’s been sober since 1992), and doesn’t shy away from sharing the realities of his struggle with Parkinson’s. The latter is evidenced in everything from physical therapy sessions and a discussion of his medication to Fox’s matter-of-fact description of falling and fracturing orbital bones, requiring the placement of metal plates in his face.

But the movie is also a fabulous showcase for the actor’s easygoing charm, both past and present. When, early in the movie, Fox takes a tumble on a sidewalk, a concerned passerby circles back and asks if he needs assistance. “Nice to meet you — you knocked me off my feet,” Fox quips. Later, when an offscreen Guggenheim notes to his subject that he can see Fox’s mind loading one-liners that he can’t quite verbally deliver, the actor nods somewhat ruefully. (Never fear, he still gets off plenty of jokes.)

Guggenheim has plenty of previous experience in using more cinematic vocabulary to flesh out and help tell nonfiction stories, most notably in the Academy Award-winning An Inconvenient Truth and especially From the Sky Down, about U2’s fraught creation of their landmark album Achtung Baby. Still, however, might just represent the director’s most impressive achievement in this regard.

Working with editor Michael Harte, Guggenheim incorporates footage from Fox’s filmography and blends it together with flashes of staged recreation and other archival footage to craft a narrative which courses with a lively, forward-leaning energy that perfectly complements its subject. Guggenheim also expertly curates a mixture of rare behind-the-scenes footage from Family Ties with other contemporaneous interview clips, balancing a look at the performer with whom so many viewers fell in love with a broader look at Fox’s family life today.

In so evocatively melding the actor-activist’s past and present, and telling his story in an engaging way that generates sympathy while eschewing cheap pity, Still makes a powerful statement about living and loving.