Chennai, Feb 10: Actor Ajith Kumar's physical makeover for his next Tamil outing "Vivegam" has stunned everybody, including those who have often criticised him for not being fit. His colleagues describe his transformation as "inspiring" and "age-defying".

When the film's first poster featuring 45-year-old Ajith with his six-pack abs was released last week, it sent his fans into a tizzy.

While a lot of people expressed awe over Ajith's transformation, actor Kabir Singh Duhan said he has only admiration and respect. Kabir had worked with the 45-year-old star in 2015 Tamil blockbuster "Vedalam".

"At his age, it's very difficult to get into shape. When we were shooting for 'Vedalam', I remember Ajith sir telling me that he was very keen on becoming fit. He even asked me if he should quit smoking and what kind of lifestyle he should adopt. I even gave him my diet plan," model-turned-actor Kabir told IANS.

"I was not surprised, but very happy when I saw the poster. My admiration for him grew by leaps and bounds," he said.

With a long medical history of injuries and surgeries, what Ajith has achieved is commendable and inspiring, says Pia Bajpai, who worked with him in 2008 Tamil actioner "Aegan".

Over the years, Ajith has undergone several surgeries including the latest one in his knee and shoulder in 2015.

"It's very tough to be healthy -- forget staying fit -- when you have a long medical history. It takes so much hard work just to lose 2-3 kg. Imagine his sheer dedication to transform his whole body. It's definitely not everybody's cup of tea," Pia said.

As a fitness fanatic, she believes what's more important than building body, is the process of maintaining it. "The effort to maintain what one has achieved through the course of the shoot is the real challenge. It's a long journey and every single day is a fight," explained Pia.

Actor Ashwin Kakumanu says Ajith's chiseled look didn't surprise him.

"He's someone who, when he puts his mind to something, goes all out to achieve it. When we were shooting for 'Mankatha', he had started to lose weight and look younger for 'Billa 2' since it was a prequel to 'Billa'.

"He was very committed and started eating only boiled vegetables," he said, and added that equal credit should also go to director Siva, with whom Ajith had worked in "Vedalam".

"Vivegam" is being directed by Siva, and it's the third time in a row he has teamed up with Ajith after "Veeram" and "Vedalam".

"Siva sir wanted Ajith sir to have this look for a while. At one point, I remember Ajith sir even telling me that he was waiting for the right project and right time to get into shape. Everything must have fallen in place with 'Vivegam'," he added.

Ashwin also said Ajith doesn't need to prove a point to anyone with what he has achieved. "He just wanted to show himself that he could do it. I don't think he did it for anyone else," he said.

"Mankatha" director Venkat Prabhu describes the transformation as "inspiring". "What I saw was mind blowing. With his medical history, what he has achieved is very inspiring. It's because of the surgeries over the years that he gained weight. Otherwise, he has been fit mostly," Prabhu said.

In "Vivegam", Ajith plays a secret agent and his role has a lot of scope for action. He is paired with Kajal Aggarwal in the film.

Ajith\'s transformation for \'Vivegam\' inspiring, age-defying, say colleagues