NEW YORK — The new PBS documentary on dancer-choreographer Twyla Tharp is known as”Twyla Moves.” In retrospect, that seems a bit feeble.

It really should be called”Twyla Moves And Won’t Quit As Long As She’s a Detectable Pulse,” a name that might perhaps start to catch the fierceness with which Tharp, who turns 80 this year, approaches both work and life.

It’s a fierceness that directed her at one stage to take boxing lessons with Teddy Atlas, who coached Mike Tyson, to get in the best possible state for a bit she was performing. “I eventually had to stop boxing because I got hit and broke my nose,” she recalled in an interview this week. “I said, ‘OK, your boxing days are over. ”’

It’s also a fierceness that greets you the moment you begin a telephone conversation with Tharp, whose words fall out with striking speed and rarely a second of hesitation. She does not need long to formulate fully developed ideas — nor does she seem to enjoy wasting time. In a current Zoom group event, she had been asked why she had not done more pictures. She proceeded to immediately list those she had done –“Hair,””White Nights” and”Amadeus” among them — with only a hint of impatience.

Considering everything, it would appear obvious that something such as a global pandemic would not force Tharp off path, or keep her on the couch binge-watching Netflix. On a recent afternoon, Tharp started a conversation by explaining why she had had to postpone a few hours: Since 4 a.m. that afternoon she’d been choreographing a new work with ballet dancers in Düsseldorf, Germany. Choreography through Zoom, she noticed,”is quite strenuous — very limited from a sensory point of view.”

And perhaps especially for a choreographer such as Tharp, who does not simply sit instruct dancers — she teaches by revealing, even today. To maintain that kind of shape approaching one’s ninth decade on earth is a struggle that would elude most people. Part of Tharp’s physical regimen entails adhering to 1,200 calories a day.

“I don’t like carrying extra weight,” she states. “I like feeling that which I call’about the bone,’ literally quite near the bone. For one thing that the feet have suffered a certain amount of abuse, and I like to maintain as much weight as you can from them.”

It’s shocking she hasn’t permanently damaged those toes. To say Tharp’s choreography is merely athletic would be to understate the manner by which it’s stretched her artists and herself to the limits. Billy Joel, who collaborated with Tharp about the 2002 Broadway hit”Movin’ Out,” put to his music, speaks of being in rehearsal and watching dancers”throwing themselves around the stage — I had been concerned about people getting injured! I felt like, ‘Take it easy! Watch out at the end of the stage!’ They had been risking life and limb every evening.”

These were topnotch dancers and she had been pushing them to the limitations of the things they could do ,” he says in the film.

Tharp explains it simply:”Part of the experience for me has always been a physical challenge.” She notes matter-of-factly that at one point in her weight loss training, she could lift 227 lbs,”and I am 108 lbs, so that’s twice my body fat. I go for documents and that is what I do. I believe anyone who works with me anticipates that exact same challenge.”

Needless to say, Tharp doesn’t appear to care a lot about physical comfort — or relaxation of any sort. Ask, by way of instance, whether she had been comfortable being the topic of a documentary, and she says drily:”I’m unsure what you mean by comfortable.” Interesting? Nah. “It’s work, like anything else. I really don’t attach to it products like comfort or pleasure.”

Indeed, the theme itself is work. In one old clip, TV host Dick Cavett asks Tharp what she does to unwind after a long duration of work. You believe her.

Tharp did not need the movie, directed by Steven Cantor and a portion of the American Masters series, to feel as a biography. She wanted a lot more present tense in there. “Often when you’re dealing with something which has as much background as I do or backlog, you may get lost before,” she states. “One of my conditions was that I’d be doing work.”

We watch her creating a fresh Zoom version of her work”The Princess and the Goblin,” with many prominent dancers handpicked for the film, including Misty Copeland of American Ballet Theatre, Maria Khoreva of the Mariinsky Ballet in Russia, Herman Cornejo of ABT, along with Charlie Hodges, a longtime Tharp celebrity. “Part of the assignment here was that dance is always about getting the job done, which even under the most difficult of situations — no actual contact, good luck with this if your’e a dancer! — we can still send something, because we are dancers. We will do it!”

However, the stone is her archive, which crosses her career, beginning with her experiments in modern dance from the’60s. There are snippets from stone like the popular”In the Upper Room,” a ballet set to the propulsive music of Philip Glass. Tharp began videotaping her job in 1968. “I have many many many thousands of hours of tape thoroughly recording every piece I’ve ever made,” she states,”since I am an art historian.”

There’s nowhere near enough time to include her vast repertoire. About half the series is on the Zoom job — 41 minutes, ” she notes with a choreographer’s precision –“and that leaves one with 20 from if you’re born to grew up and you’re not not quite dead yet, then another 20 for 150 works and four novels…”

And she’s not near done. Asked in the film whether she’s achieved her mission, she says:”Not quite.” Inspired by this reporter when that might be, she provided:”When I die?”

“There is nothing that could hold Twyla back out of creating — it feeds her,” says Copeland from the movie. “We are all trying to keep up with her, is the moral of the story.”