Actor Kartik Aaryan braved high fever, shoulder injury and neck pain while shooting the swimming scenes for Chandu Champion after undergoing intense training in order to appear like a professional swimmer on screen, he has revealed in a new behind-the-scenes video.

“I was never a swimmer. I can never imagine myself staying a swimmer,” the 33-year-old actor says in the video on Instagram. It chronicles his entire swimming journey from the day he started learning the activity to the moment he aced the Olympic scene in the film.

Kartik’s swimming trainer admitted in the video that the actor’s technique and style were not up to the mark when he began to swim. “Training him to look like an Olympic champion was not easy at all,” the trainer says.

Since Kartik was learning the sport in a short time, he constantly suffered from shoulder injuries. The actor frequently required rehab and ice bath sessions to recover, his physiotherapist said.

“It was amazing how fast he could learn and make it look like he was competing against these athletes,” director Kabir Khan said in the video.

Even when he was down with 101 degrees fever, Kartik did not stop training. He also opened up about how the chlorine in the water would hurt his eyes and he would constantly have to use eye drops. Giving expressions while swimming was also a difficult task for the actor.

When the swimming scene was shot for the film, the cast and crew realised how Kartik is faster than many professional swimmers. “Shooting for the scene was so difficult, which makes me wonder how Murli ji actually did it in real life,” Kartik said at the end of the video.

“From a Non-swimmer to Swimming with all the Swimming-Champions, Have learnt so much in this incredible journey, Big Thanx to my trainer @virdhawal for being so patient,” the Satyaprem Ki Katha actor wrote in the caption.

Chandu Champion is a biographical drama based on the life of India's first Paralympic champion Murlikant Petkar, who represented India at the Olympic Games and won a gold medal in the 1972 Summer Paralympics. The film portrays Murlikant’s struggles and triumphs, right from his journey as a boxer in the Indian Army to his achievements as a Paralympian swimmer.

Apart from Kartik featuring in the titular role, Chandu Champion also stars Vijay Raaz, Brijendra Kala, Rajpal Yadav and Bhuvan Arora.

Kartik is currently shooting for his upcoming horror comedy Bhool Bhulaiyaa 3, which also stars Triptii Dimri and Vidya Balan. The actor recently appeared on the finale episode of Netflix India comedy show The Great Indian Kapil show along with his mother Mala Tiwari.