NEW YORK — If you see Imagine Dragons lead singer Dan Reynolds out in public and you think he’s ignoring you — he isn’t, he’s just trying to stay ready for his live concerts.

“I’ll wear a sign typically that says ‘vocal silence,’ then like a frowny face, and I’ll put that on anytime that I have a day off,” said the 30-year-old rocker, whose Evolve World Tour arrives July 13 at the Hollywood Casino Amphitheatre.

“Two-hour shows that many days a week is just intense. Intense.”

Imagine Dragons, Grace VanderWaal
When: 7 p.m. Friday
Where: Hollywood Casino Amphitheatre, Tinley Park
Price: $50 – $190
Info: livenation.com

The Grammy-winning quartet is known for powerful live performances, with Reynolds working the entire stage with full energy during hits like “Radioactive” and “Believer.”

“It’s just like being a professional athlete, except for your voice. You have to take it that seriously at this level. I don’t know how artists maintain (themselves) on the road and live an unhealthy lifestyle. Actually they don’t. Those are the bands I think that break up, they cancel a lot of show dates, or they just sound really bad live,” he said. “I don’t want any of those options.”

He said his band has “canceled, I think, one show in our career and we’ve played thousands and thousands of shows.”

Reynolds breaks down what he does to stay healthy and fit on the road.

IT’S NOT FOOD, IT’S FUEL

Reynolds could easily afford a personal chef while on the road — but it would be a waste of money: His diet is super basic and doesn’t change.

“I’m such a creature of habit. When I’m on the road I really become so boring. … Food is just fuel for me. It’s not like an enjoyable thing,” he said. “When I’m on the road it turns into, ‘What is the cleanest source of energy for me?’ I eat really the same thing every day.”

The American pop rock band Imagine Dragons with lead guitarist Wayne Sermon, percussionist and lead vocalist Dan Reynolds and drummer Daniel Platzman performs at the Xfinity Center, Wednesday, June 6, 2018, in Mansfield, Mass. | Robert E. Klein/Invision/AP

He’ll have oatmeal and eggs for breakfast, while lunch and dinner could range from chicken to fish or lamb, along with brown rice, vegetables or sweet potatoes. He cuts out all sugar, bread and dairy.

Reynolds says he’ll eat every 90 minutes until about three-to-four hours before he hits the stage because he prefers to sing on an empty stomach.

“That gives me a lot more to pull from, so you’re not burping onstage and you’re not having any acid reflux or anything,” he said.

“I don’t eat when I get off stage either,” he added. “I try to go to bed right after.”

EXERCISING THE DEMONS

Now a personal trainer is something Reynolds needs on the road.

Part of the reason for that is because the singer has ankylosing spondylitis, a form of arthritis that causes inflammation of the spinal joints that can lead to severe, chronic pain and discomfort.

“One of the best ways to thwart it off without taking immunosuppressants is to really get your blood flowing through your whole body and all your joints every single day. You have to be really active, long story short,” he explained.

“A two-hour show every night, it’s not enough for me to keep the inflammation at bay. Really what does that is a lot of power lifting, a lot of Olympic lifting, so that’s really what I’m focused on with my trainer,” he added.

Reynolds says he also works out daily “for my mental sanity, just because it keeps me happy.”

NO, NO, NO TO H2O

When Beyonce slayed at Coachella this year, some noted that she performed for nearly two hours without a single drop of water.

But Reynolds said that may have been on purpose.

“Even though that might sound like … she couldn’t find time for it, it also very well may be a conscious choice just as a singer,” he said. “For instance, if you’re drinking too much water, your diaphragm, it makes it harder to sing. It’s kind of an old wives’ tale that you need to drink water when you’re singing to sound better.”

However, before shows Reynolds says he drinks lots of water — about a gallon a day — which helps him when he’s not taking water breaks during his shows.

Keeping his voice strong is his priority.

“You have to really maintain a strict regimen,” he said. “Especially when what you’re singing requires a lot of power and air, which Imagine Dragons songs definitely do.”

In this Feb. 1, 2018 file photo, Dan Reynolds, lead singer of Imagine Dragons, performs at the EA Sports Bowl in Minneapolis.| Omar Vega/Invision/AP, File