Jake Gyllenhaal has made much of his daily six-hour fitness regime and how he got into shape to play Billy Hope, the hero of boxing movie Southpaw**, and part originally intended to be played by rapper Eminem.

Jake clearly did the reps and the sit-ups and the crunches. Although in repose his ripped midriff can gather to look like the folds of skin on a prize pug’s neck, his abs are terrific; shame about the script.

The Southpaw of the title refers to a boxer who leads with an unorthodox left hand but that’s as surprising as this movie ever gets. From the first bell to the finale, it’s a slog through countless boxing movie cliches, with barely any fancy footwork, dodging or weaving.

Slugger Billy has fought his way up from the streets and a life “in the system” to become world champ, with an enormous house, an entourage of idiot friends and a ridiculously venal manager, played quite hopelessly by 50 Cent. He’s also got a wife Mo (Rachel McAdams) and a 10-year-old daughter. “We’re all that matters,”  Mo admonishes Billy while nursing his bruises on the night of his latest big win.

Soon enough, and totally unbelievably, Billy ‘s life falls apart. In one quick montage, he loses his house, his possessions, his manager, his boxing license and his daughter. And before you can say Burgess Meredith, Billy goes back to basics, to a shabby 156th Street  gym, run by a shabby, one-eyed but all-seeing trainer, played by Forest Whitaker like he’s still Ghost Dog, spouting Samurai sayings like: “Boxing is a game of chess”; “Boxing isn’t about your fists, it’s about your mind.”

With Billy desperate to get his daughter out of social services and even more desperate to earn some money, he accepts a title fight in Vegas. Cue training montage set to shouting Eminem song Phenomenon with Billy doing strange routines involving string and having a medicine ball hurled into that ripped tummy, while his upcoming opponent, the dastardly Colombian Miguel Escobar, does his cocky thing in another ring. It makes Rocky IV look sophisticated.

There’s still room for an insultingly thankless social worker part for Naomie Harris, some awfully cliched commentary work (“this is a war of attrition folks, and a shot at redemption for Hope,”) and a big fight which still had me shouting for Billy even if he’s barely earned my sympathies as a character, apart from being played by the generally appealing Gyllenhaal.

I love boxing movies usually (apparently, this started out life as an intended remake of Jon Voight-starrer The Champ) but Southpaw is barely a sparring partner for any of the good ones and even most of the bad one. Compared to Somebody Up There Likes Me, Rocky, Raging Bull, The Boxer, and even The Fighter, this is just shadow boxing.