To get into shape as the sprinter he plays in the upcoming film “Bhaag Milkha Bhaag,” Farhan Akhtar has subsisted on egg whites, grilled fish and protein shakes for the past year. “I’ve been dying to eat roti,” says the 39-year-old Bollywood star. “Bhaag Milkha Bhaag,” Hindi for “Run Milkha Run,” chronicles the life of Milkha Singh, the Indian nicknamed “the Flying Sikh.” For years considered the great hope by a country with a paltry Olympic record, he competed at three Games, including 1960, where he came within a fraction of a second of winning the 400-meter bronze medal. The film, shot in villages in the northern state of Punjab, as well as Italy, Japan, Australia and Thailand, opens in India on July 12. Mr. Akhtar, who was born and raised in Mumbai, first attracted notice as a director, with the 2001 coming-of-age romantic comedy “Dil Chahta Hai.” Loosely inspired by his own college escapades, the movie attained cult status over the years, positioning him as a pioneering voice in contemporary Indian film.

His popularity peaked in 2006 when he directed “Don,” a crime drama starring Shah Rukh Khan as a drug lord. In 2011, the sequel, “Don 2,” became the third-highest grossing film in the 100-year history of Hindi cinema. Mr. Akhtar made his acting debut in the 2008 musical-drama “Rock On” and has since dabbled with many facets of filmmaking, from screenwriting to soundtracks. He spoke with the Journal about his “Bhaag Milkha Bhaag” training regime, how his fascination for films got him expelled from college, and why he is shamed by the status of women in India. Edited excerpts follow. The Wall Street Journal: How did you prepare for “Bhaag Milkha Bhaag”? Mr. Akhtar: My character is based on the life of a legendary sprinter. So the first step, really, was to learn to how to run like one. I hired a track-and-field coach—one who has worked with national athletes in the past—to teach me basics on the field. Another trainer chalked out a workout routine and a high-protein diet. For about a year and a half, until we finished shooting the film, I lived in the skin of my character. A typical day would include at least five hours of training, from maximizing acceleration on the track to sweating it out with cardio workouts in the gym.