How to sculpt a <i>killer</i> physique like Patrick Bateman from <i>American Psycho: The Musical</i>.

The Patrick Bateman physique doesn’t happen by itself. Mr Benjamin Walker, who stars as the homicidal maniac in the new Broadway incarnation of hit musical American Psycho works out four mornings a week with Mr Rich Barretta, a former Mr America whose “target training” technique incorporates old-school bodybuilding methods. Here’s a rundown of his workout schedule.

“We wanted a guy who’s narcissistic, with a body that fits really well in clothes,” Mr Barretta explains. “The focus was more on the shoulders and back muscles, to make him scarier. We didn’t want to overdo the chest. And we refined the abs, without making him look like a magazine model.”

Mr Walker completes six rounds per workout: two different circuits, three times each. A circuit combines a “super set” (consecutive exercises working different muscles) with a “giant set” (same muscles, different angle, eg, push-ups followed by cable crossover) and consists of more than 100 total reps.

Example round: incline barbell, pull-ups, cable crossover, bent-over rows, push-ups, deadlift, with “jack knives” (targeting abs) for good measure.

Between rounds, Mr Walker grabs a drink of water and spends two minutes skipping. Somehow, he completes the whole routine within an hour, including five to eight minutes at the end for stretching. He also skips for half an hour at the theatre every day. On non-workout days, he spends at least 30 minutes biking, running or skipping. “The purpose of the cardio is to burn extra calories, which will help reduce subcutaneous fat and help show off the body we’ve built,” says Mr Barretta.

Mr Barretta charged Mr Walker with cutting out all alcohol, bread and sugar. Breakfast is egg whites or high-fibre cereal with low-fat milk. Staples for other meals include sweet potatoes, black or brown rice, greens and legumes, such as lentils, black beans and chickpeas. Salmon and other cold-water fish provide healthy omega-3 fats, while nuts and seeds provide both omega-3 and 6. Mr Walker sips protein shakes throughout the day. Pleasure in eating is not a priority. “Oranges taste like ice cream to me at this point,” he says. “Turkey meatballs have been my salvation.”

Read the full interview with Mr Walker here