Ajay Devgn and Mrunal Thakur are busy promoting their upcoming film, Son of Sardaar 2. Recently, during one of their promotional events, Mrunal spilt the beans on Ajay's fitness routine. The actress joked that the action star's secret to staying fit for so long is hitting the gym between shots. Mrunal shared, "Whenever we were on set, since I was shooting with so many actors for the first time, there was always food around. But when sir would sit aside, we'd be watching our diets, and even between shots, while we'd be chatting or gossiping, he would go and work out.