Superstar Shah Rukh Khan has been defying health warnings and spending long hours at work.

Shah Rukh, who underwent a shoulder surgery in May, has been juggling with multiple tasks of late.

Post surgery, he was advised at least 10 hours of sleep to help his weak shoulder recuperate faster. But just last week, King Khan shot a tough song with his "Chennai Express" co-star Deepika Padukone. He was busy for two days with the song.

On the third day, he shot an ad too! Also, he busies himself with dubbing for "Chennai Express" till early hours in the morning, and reaches home in time enough just for about four hours of sleep before he wakes up at 8 a.m., said a source.

Then he sets out for his meetings.

Shah Rukh was also advised to avoid crowded public places, but for a star of his stature, that becomes a tad tough, especially when he is caught in the midst of promotions for "Chennai Express".

The movie, directed by Rohit Shetty, releases on Eid Aug 9.