Since his first appearance in the Bollywood industry a decade ago, Rakesh Roshan's loving son is tagged as the best dancing star, but the elegant actor emphasizes that rehearsals are vital before starting the shoot.

A source disclosed, "Hrithik lives, eats, breathes and dreams (literally) of dance just a week before shootings begin! No matter how hectic his schedule or work commitments, he rehearses his steps with the concerned choreographer days in advance."

The actor starts work on the 'Agneepath' song this week and has been quietly practicing in spite of film shooting all day, and exercising for an hour and half during day and night for the song for a period of one week.

"Next he will have to shoot three music videos for the dance reality show 'Just Dance' he's judging. For each song, rehearsals begin a week earlier," the source added.

Agneepath maker Karan Johar thinks that the actor is a relentless practice man.

"Exhausting hours result in effortless moves - that's Hrithik for you. He raises the bar of excellence and validates the input equals output theory," KJo stated.

On this, Junior Roshan said that together with rehearsals, he truly learns dancing during sleep.

"If I can clearly see every moment of the move in my head, then my body is able to express it... The downside is that if I can't see it - I can't do it."

Karan, who previously directed Hrithik in the 2001 mega hit 'Kabhie Khushi Kabhi Gham', recounts a earlier experience, "We had two hours to shoot at the British Museum. Hrithik was given an elaborate dance piece that could have thrown anyone off, even internationally, but he worked through the night and came straight to shoot. It took just one take and we were done and out of there!"