We don’t even want to know how hard Jake Gyllenhaal trained and bulked up to play a down and out fighter in Southpaw. It’s too bad all that obsessive Christian Bale-worthy physical transformation just wasn’t worth it for Southpaw – the same damn boxing movie people have been making and audiences loving since the ‘30s.

Scripted by Kurt Sutter (Sons of Anarchy) and directed by Antoine Fuqua, this thing doesn’t miss a cliché of the genre. Gyllenhaal, mumbling so heavily that he almost approaches Tom Hardy’s unintelligibility, plays a light heavyweight champ named Billy ‘The Great’ Hope. Yeah, this movie is that on the nose. He’s overcome a tough childhood in a brutal Hell’s Kitchen orphanage and, at the start of the flick, he’s a rage-filled, Method-y cock of the walk.

With an unbroken string of 43 victories in the ring, Billy’s got a great childhood sweetheart wife who dutifully frets that he needs to slow down. Rachel McAdams is so good at playing her that it’s no wonder she’s been inescapable lately. Also solidly in his corner are an adored daughter (Oona Laurence, terrific), and a tough, effective promoter (50 Cent). Then, just as our hero is about to hang up his gloves, he pretty much goes to hell in a hand-basket and loses it all – in about two minutes of screen time. It’s so bad that his kid’s going to be torn away from him. Scraping the bottom of the barrel, he wanders into a ratty old gym and, with the help of grizzled vet trainer Tick Willis (Forest Whitaker), he slugs his way back to redemption, accompanied by the obligatory rousing training montages, soundtrack contributions by Eminem (who was once supposed to star in this thing), muscular sped-up fight sequences, and lots of Gyllenhaal suffering and sweating like a ripped, galoot Jesus.

Props to the actor who, with Prisoners, Enemies, and Nightcrawler and, from all we hear, the upcoming Everest, has been pulling off one of the more astonishing career overhauls in recent Hollywood history. He’s the real reason to see this. Southpaw has its problems but it also has a big heart and it’s so full of mushy, irresistible redemption that you might leave the theater with a case of punch-drunk love.