Incredibly boring or remarkably evocative? That’s the question Frederick Wiseman’s “Boxing Gym” raises, just as it’s been raised about virtually all of the uncompromisingly “unobtrusive” documentaries the director’s made over the years. Even at little more than ninety minutes—a fraction of the time Wiseman has spent on other places—the picture can seem very long and repetitive. On the other hand, those acutely attuned to the director’s approach will probably find it hypnotically compelling.

As suggested by the title, the picture isn’t really about boxing per se. Apart from some sparring scenes, it’s mostly about individuals training alone at Lord’s Gym in Austin, Texas. Some are youngsters, others significantly older, and they come from very different walks of life. We watch them in extended sequences as they do calisthenics, punch at bags or the air, engage in weightlifting routines and the like. There are no direct interviews. In his usual fashion, Wiseman eavesdrops on their conversations, with Lord talking to his customers, sometimes while he works with them in the ring, and them talking among themselves. But these are mere snippets that show the enthusiasm the subjects have for boxing and what it’s done for them, and while some of them are fairly interesting, they’re certainly not intended to build into a larger argument or overarching statement about pugilism.

The point of “Boxing Gym” is pretty much the same as Wiseman’s last film, the much longer “La Danse,” which focused on the incredible effort that goes into the preparation of ballet dancers. The point here is that boxers, or those who simply use the training regimen of boxers as a mode of exercise, work just as hard as dancers, and Wiseman finds it exhilarating and revealing to watch them as they do so. Whether you agree will determine your reaction to the result, just as it does with his earlier films.

Of course, this film, like all of Wiseman’s work, raises questions about how “fly-on-the-wall” his technique actually is. It’s the cinematic version of the Heisenberg Principle—to what extent does the mere presence of the camera affect what it records? It’s certainly clear that the editing, which aims for a random feel, is actually quite manipulative: all one needs to do is mull over the evocative outdoor shots with which he chooses to close the film to realize that.

Still, “Boxing Gym” is of a piece with Wiseman’s filmmaking philosophy, and fits snugly into the whole of his work, even if—as compared to the similarly-themed “La Danse”—it’s a relatively minor example of it, at least in terms of length.