The Boxing Workout Jake Gyllenhaal Used to Get Seriously Shredded for ‘Southpaw’

Besides starring in some of Hollywood's most successful films, there's another common denominator between the likes of Zac Efron, Tom Hardy and Jake Gyllenhaal—they've all used bodyweight exercises and home-friendly workouts to build a physique that would be remembered years after their starring role. One of Gyllenhaal's most famous (and, frankly, intimidating) roles was portrayal…