Mckenna Grace's body was in "fight-or-flight mode" while shooting Sunrise on the Reaping.

The 20-year-old actress stars in Sunrise on the Reaping, the upcoming prequel to the beloved Hunger Games franchise, and Mckenna admits that the movie's shoot took a heavy toll on her.

She told People: "Whenever you're putting your body in fight-or-flight mode every day, your body can't tell the difference between the trauma of that and if you were really running for your life.

"So it's like you go home every day and your nerves are totally shot and you're out of your mind like, 'Oh my God, I almost died today.' And you're like, 'Yeah, I did do some dangerous stunts,' but it's more so the emotional impact of that."

Mckenna spent weeks preparing for her role in the movie. However, she was surprised that it took such a heavy toll on her.

The actress said: "I was also unprepared for the amount of cardio I was doing every day on set.

"I trained for a few weeks for Hunger Games in the gym. I had a whole workout regimen and I was like, 'There's no way I'm ever going to be needing to do this much cardio,' to my trainer. I was like, 'This is ridiculous' ... it was not ridiculous."

On reflection, Mckenna now suspects she might have been underprepared for the role.

She said: "If anything, I felt underprepared. It was insane. I felt like I was in the Hunger Games for real with how physical that arena stuff was."

Meanwhile, Mckenna previously claimed that she relishes having a busy work schedule.

The actress explained that she always wants to return to work - regardless of how hectic her life feels.

She told Teen Vogue: "It is tiring at times, but I dig it.

"Grass is always greener. I'd rather be doing 20 million things at once than just sitting at home and being like, 'Shoot. When can I get back to work?'"

The Hollywood star also explained that she can manipulate herself into feeling positive.

She said: "It sounds really terrible when I put it this way, but I feel like some days I just gaslight myself into being happy or energetic."

Mckenna insists that her work ethic hasn't been diminished by fame and success.

The actress - who starred as a child prodigy in Gifted, the 2017 drama film - reflected: "I'm 14 years into being in the industry, and I still work just as hard as the day that I got to Los Angeles."