Mumbai, Sep 30 : Actor Tarun Khanna, who is popular for playing Lord Shiv on the small screen, says fitness is like oxygen to him. "Fitness means the world to me. When I was a kid, I was very weak. I used to fall sick frequently. In my growing-up years, people often made fun of me and that was the time when I made a resolution that I will never be weak. Since then, fitness has been like oxygen to me," he said. His roles also demand him to stay fit. "I have played the role of Mahadev eight times on different platforms. That requires me to bare my upper torso. Hence, to flaunt that, you need to have a proper physique. I don't make it overly muscular but I make it look athletic," he said. To keep a healthy balance between his mind and body, he does yoga. "I don't do yoga everyday but I make sure I do it at least four times a week. It definitely helps me strike the right balance between my physical and mental fitness," he shared. Tarun is currently seen in Sony SAB's "Tenali Rama". /IANS