When it comes to getting an actor to look at beefy as possible, without the typical cliched aesthetic of looking like they’d just stepped straight on-set from a body-building competition, down time is everything. Waterson explains that a key concern was that Gyllenhaal’s character carried a sword on his back and, should his neck and shoulders get too big, he wouldn’t be able to draw the sword from its sheath.
Alongside mobility work, the pair worked on increasing Gyllenhaal’s flexibility. It meant that if he struggled to draw the sword or sprint without panting, they would dial down the weightlifting and focus on other areas.
While training began in London, the filming was on set in Morocco, with no fixed gym facilities. This meant improvising early morning workouts. “Because of the heat in Morocco and the filming schedule we’d get up and work out at 4am,” says Waterson. “It was vital to keep him fuelled and hydrated throughout the day. We were also filming during Ramadan, so it became a tough place to work with sustained bursts of energy when everyone else is absolutely exhausted.”
For the diet, Gyllenhaal ate about 4,000-4,500 calories a day. They provided fuel but also served as building blocks of muscle. “I never cut food groups,” says Waterson of Gyllenhaal’s diet. “I’m very balanced to make sure I have enough calories from a carbohydrate source to sustain energy, then enough from a protein to be able to make sure that the repair mechanism is there, and then good fats and good hydration. It’s simplistic and balanced but it’s nutritionally relevant to what he was trying to achieve.”
With training taking place around an exhausting film schedule, recovery was critical to avoid injury. To address this, Waterson ensured a physiotherapist was always on hand to deliver the required treatments from massages to stretches. As for the other aspects, it was fairly straightforward: stretch, drink water, get enough sleep and be good to your body.
If you’re looking for a workout Jake Gyllenhaal did for his Prince of Persia role, look at the one Waterson shared with Men’s Health UK here.