Mumbai, Aug 13 (IANS): Actor Sidharth Malhotra, who had to gain 12 kg for "Brothers", says he became nervous and scared when he came to know that he had to fight with Bollywood's action star Akshay Kumar in the movie.

"I was nervous and anxious when I signed the movie. We have seen and we like Akshay Kumar's action work. When I got to know that I had to fight with him for the climax, I was a bit scared," Sidharth said here.

However, he convinced himself to do it.

"To do anything convincingly, we need time, and I did it. For four months, I didn't do anything. I used to train as a fighter, gym and have meals to increase my weight," said the "Student Of The Year" actor.

"I gained 12 kg and Akshay sir lost 12 kg for the movie, and the tough part was to maintain it after a day of action and gymming," he added.

Sidharth will be seen punching Akshay in the movie.

Talking about it, he said: "It was a choreographed punch, not a real one. It was difficult for both. For the punch to look good on screen, the reaction of the other person has to be right. Akshay sir knew the nuances.

"The difficult part was to remember the sequence of kicks and punches. I memorised it like a dance sequence and used to rehearse a lot," he said.

The team also made complete use of Akshay's experience.

"We used Akshay sir's experience. He knows all the safety norms, which action will look right and what will be impactful. We enjoyed a lot and learnt a lot from Akshay sir. His time and team management behind the scenes was worth learning," said Sidharth.

What else did Sidharth learn from Akshay?

"There is a lot to learn from Akshay sir... how he handles his life, his shoot, his timing and the activities he does in one day. The discipline he and his team has. And all this in a relaxed manner... I have never seen him stressed or angry and that is very encouraging," he said.

Directed by Karan Malhotra, "Brothers" is releasing on August 14. It also stars Jacqueline Fernandez.