Actress Katrina Kaif, who is just back from a tough London schedule for her upcoming untitled movie to be directed by Yash Chopra and also staring Shah Rukh Khan and Anushka Sharma, will now start shooting for her very first action movie ‘Dhoom 3’. The actress recently confessed that she was nervous about the movie.

In preparation for the action movie Katrina Kaif will be undergoing rigorous training. For the next 10 days, the actress is going to be training for four hours, every day at the Yash Raj Studios where a floor has been specially rigged up for the practice sessions.

“The sessions are basically to determine what my stamina is like and how much I can take. Which is what is scaring me,” said Katrina Kaif to a daily.

The actress, who is familiar with workouts, said that she has never worked out so rigorously and put her body through so much torture.

“That kind of working out is just too draining. Particularly, when you are not used to that kind of extreme physical strain. Your body ends up feeling worn out. It starts craving…you know…rest and food. After those four hours of working out, I will be like dead for the rest of the day,” she said.

The actress is really impressed with the way her ‘Dhoom 3’ co-star Aamir Khan has maintained a body over the years.

“That kind of working out is just too draining. Particularly, when you are not used to that kind of extreme physical strain. Your body ends up feeling worn out. It starts craving…you know…rest and food. After those four hours of working out, I will be like dead for the rest of the day,” she said.

“However, I thought that if I needed to do a role of this kind, it had to be now. I won't be able to do justice to such roles after I get into my 30s,” she added.

Katrina Kaif admitted that the role is ‘Dhoom 3’ was a huge challenge.

“I don't think my body is very flexible. What if they find I can't do some of the things required for the scenes? This is a huge challenge; sometimes I don't know why I sign up for such roles. Why can't I just stick to the sarees, eat what I want and be happy?” she concluded.

‘Dhoom 3’ is scheduled to release next year and stars Aamir Khan, Katrina Kaif, Abhishek Bachchan and Uday Chopra.