There’s a thin line between downtime and wasting time.

We’re inundated with statistics and stories about how we’re all overscheduled and under-rested. “Busy-ness,” described as both a virtue and an epidemic, inspires countless blog posts and a healthy number of books.

“Always behind and always late, with one more thing and one more thing and one more thing to do before rushing out the door,” Washington Post reporter Brigid Schulte writes in “Overwhelmed: Work, Love, and Play When No One Has the Time” (Picador), the 2014 book widely heralded as a must-read.

It’s little wonder, then, that we crave — and find — ways to decompress, often through pursuits that don’t add much to our lives. Clicking through your college boyfriend’s vacation photos on Facebook, for example. Candy Crushing your pals.

But is that a good or a bad thing? Experts warn parents and educators against overscheduling children, whose growing minds and bodies need downtime to develop in every realm: social, emotional, academic and physical. But we don’t spend as much energy defending unstructured time for adults.

“There’s a stigma around downtime,” said Shimi Kang, a Harvard-trained child and adult psychiatrist and author of “The Self-Motivated Kid: How to Raise Happy, Healthy Children Who Know What They Want and Go After It (Without Being Told)” (Tarcher/Penguin).

“It sounds a little woo-woo to say you prioritize rest,” she said. “People judge you as not very ambitious, not very competitive.”

In truth, Kang said, restorative downtime is critical for our mental and physical health.

“Breaks are moments of breakthroughs,” Kang said. “Certain biological processes occur exclusively during moments of relaxed wakefulness, when the brain’s default-mode network becomes activated.”

Productivity, problem-solving, attention, creativity, a moral compass — all are strengthened and improved when our bodies have a chance to rest, Kang said.

“A time of relaxed wakefulness is when we integrate what we’ve felt or heard,” she said. “It’s when we make sense of our past and apply it to our future, so our sense of ethics, our sense of self, even empathy, are all shown to improve.”

But all downtime is not created equal, said time-use expert Laura Vanderkam, author of “I Know How She Does It: How Successful Women Make the Most of Their Time” (Portfolio/Penguin).

“There’s a big difference between consciously doing nothing versus actually wasting time,” Vanderkam said. “Wasting time is spending it on things that aren’t particularly meaningful or even enjoyable to you.”

Surfing channels for an hour is wasting time, she said. Watching an episode or two of your favorite show, on the other hand, is healthy downtime.

“You want to make sure downtime is doing what it’s supposed to do, which is rejuvenate you so you can return to your busy life more refreshed,” Vanderkam said. “If it’s not adding to your energy levels, you may want to stop doing it.”

That doesn’t mean you have to spend your downtime reading Tolstoy.

“We’ve gotten this idea that we have to be productive every second,” said Rachel Macy Stafford, author of “Hands Free Life: 9 Habits for Overcoming Distraction, Living Better and Loving More” (Zondervan, due out in September). “We’ve run out of times and places where we can just let our mind wander.”

Stafford said she trained herself to build “connective silences” into her days.

“I give myself permission to be all there in certain moments,” she said. “It might be sitting on the floor of my daughter’s room while she’s picking out her clothes, instead of scurrying around picking up her mess. I’m thinking about how the carpet feels, how my breathing sounds, looking at her face and taking in her freckles. It’s almost a meditative experience.”

Kang said she would like to see more medical practitioners weigh in on the need for downtime.

“We need an authoritative voice telling people to take breaks in your days, to slow down,” Kang said.

Her patients often tell her they don’t have time to build rest into their lives, Kang said. She has a ready answer.

“I tell people, then you’re too busy for optimal health,” she said. “You’re too busy to perform optimally. Too busy to be brilliant, to be the best athlete, to be the best CEO, writer, homemaker — whatever it is you’re trying to achieve. Because you need rest to do all of those things.”