Steve Zissis, left, and Mark Kelly in THE DO-DECA-PENTATHLON (Red Flag Releasing)

Released just before the start of the London Olympics, The Do-Deca-Pentathlon, the latest from Jay and Mark Duplass, is about a different kind of sports competition, one on a much smaller scale, but with very high stakes for its two participants. Intense sibling rivalry is at the center of the titular competition, and the combatants haven’t quite grown up. Their simmering childhood conflicts still drive their behavior as adults, despite the fact that one has a wife and a child in the picture.

The film opens by giving us glimpses into the parallel lives of the two estranged brothers. We first meet Mark (Steve Zissis) in a bathtub talking to his wife, Stephanie (Jennifer Lafleur), about the humiliating treatment he suffered at the hands of his brother, Jeremy (Mark Kelly), when they were both kids. Mark debates whether he should go back home to his mother’s house to celebrate his birthday, afraid that Jeremy may show up, who Mark deliberately didn’t invite. Meanwhile, Jeremy, a professional Las Vegas poker player, is becoming burned-out and bored with his life of card playing and hanging out in strip joints. Well aware that Mark doesn’t want him there, Jeremy decides to go to Mark’s birthday celebration, ostensibly to break out of his routine, but deeper reasons emerge.

Later, the brothers reunite in a very funny scene in which Mark participates in a 5K charity “fun run,” during which Jeremy suddenly shows up to challenge him. Much of the scene is shot in slow motion, mock Chariots of Fire style, and the brothers’ old rivalry immediately flares up. They play dirty, shoving each other out of the way, with Jeremy ending up bruised and bloody, and Mark’s vomit splattered on the course. The image of these two out-of-shape men, who really have no business engaging in this sort of strenuous activity, performing in intense athletic competitions is the source of most of the humor.

Soon enough, the subject is broached of “The Do-Deca-Pentathlon,” a private, homemade Olympics the two brothers engaged in as teenagers. This was a 25-event competition with such activities as arm wrestling and holding their breaths underwater. The brother who won the most events would be declared the superior brother. They decide to make a sequel in another 25-event competition that they believe will settle their differences once and for all, though their mother and Mark’s wife warn against it. Stephanie is worried about the impact on Mark’s health; he has been seeing a therapist for some time, and is on medication for various health issues. Thus, Mark and Jeremy are compelled to conduct the pentathlon part two in secret, competing under the family’s noses—taking secret trips to the YMCA and playing pool in the dead of night. And although Jeremy at first seems to be the ostensible villain, disrupting Mark’s birthday celebration by reviving old rivalries, this soon begins to shift. Mark becomes more and more obsessed with winning and settling old scores, and this silly private sports event and his single-mindedness threaten to destroy his relationship with Stephanie.

The Do-Deca-Pentathlon, although released this year, was actually shot back in 2008 and shelved while the Jay and Mark Duplass made their more high-profile and higher budgeted films Cyrus and Jeff Who Lives at Home. This latest release is a reminder of the micro-budget aesthetic of their first two films The Puffy Chair and Baghead. Similarly to their other films, the style is faux cinema verité, with a restless camera and abrupt zooms and shots not so much composed as captured on the fly. It was filmed in the Duplass’s hometown of suburban New Orleans, and the YMCA and Laser Tag places where the fictional brother’s competitions take place were where the Duplass brothers themselves used to hang out. This, along with the fact that the film was inspired by two brothers the Duplass’ knew who actually created their own sports event, lends a sense of realism and authenticity to the proceedings. And although the film can’t quite shake its tempest-in-a-teapot quality, and is ultimately a trifle, it nevertheless gets at certain truths about one’s unbreakable ties to family, and how strongly these relationships shape us as adults