To prepare for his film role as a boxer, Jake Gyllenhaal gained almost seven kilos of muscle.
In a recent Southpaw trailer, the Hollywood actor shows off shredded abs and bulked-up biceps.
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His transformation was slow, taking six months, his trainer Claybon has revealed.
“Gradually we built up, day-by-day,” the trainer told Yahoo News.
But after losing 13 kilograms for his role as a scrawny journalist in Nightcrawler, the actor’s change was stark.
Here’s how Gyllenhaal, 34, got huge.
Morning
One thousand sit ups
Three hours of boxing
Night
Another 1,000 sit ups
A further three hours of strengthening, conditioning and cardio