The world seems to be divided into two groups — enthusiastic podcast fans and those who have yet to discover the popular venue.

Podcasts, or digital audio files that can be downloaded from the internet and cover a wide variety of topics, have been around for two decades. But in recent years, their popularity has skyrocketed.

Edison Research, which tracks the industry, reported this year that more than 2 million podcasts, with more than 48 million episodes, now are available.

While 75 percent of the U.S. population Edison Research surveyed had heard of podcasts, only about 55 percent had listened to one.

But those numbers are climbing. This year, monthly podcast listenership grew to 116 million people. By the end of 2025, Edison Research expects more than 144 million Americans will be listening to podcasts regularly.

While the most popular podcasts are comedy, or about news and education topics, self-help and health podcasts have large followings, including in Kern County.

“In November 2019, I didn’t listen to podcasts at all,” recalled Christine Luther Zimmerman. “My role as a wife and mother, and my work as an advocate and technical advisor at a trade association, kept me too busy to read for pleasure, let alone listen to podcasts.

“Life changed that fall in a way that forced me to stop and listen to a lot of things. My father was diagnosed with a brain tumor and while he was recovering from surgery, my mother found a lump and was diagnosed with breast cancer. The rhythm of life screeched to a halt, with fear, anxiety and grief rewriting everything.”

Whether it was at home, or work in Bakersfield, or at work in Sacramento, Zimmerman would find herself racing outside — walking as fast and far as she could to manage her anxiety and sadness.

“Miles would fly by as I ran from what troubled me and music no longer was enough to break the grip of anxiety,” she recalled.

While riding Amtrak early one morning, thoughts of chemo, radiation and her 12-year-old daughter’s sad eyes as she left that morning consumed her.

“I closed my laptop and picked up my iPhone, flipping through the screens for something different to try. I opened the podcast app and searched ‘managing anxiety,’ then ‘managing grief,’ then randomly selected a podcast and started listening.”

By the following March, the COVID-19 pandemic brought the world to a screeching halt.

“Nothing was the same except for my parents’ cancer treatments,” she recalled, adding that new health woes, and school and work from home added an extra layer of fear and anxiety. “This halt brought endless opportunity to walk and listen.”

Some of Zimmerman’s favorite podcasts now are Eric Zimmer’s “The One You Feed,” which includes interviews with authors, artists, scientists, philosophers, all sorts of folks, with focus on resiliency, mental health, creativity, grit under pressure — a vast range of mental health and survival tips for this life. Another favorite is “The Mindset Changing Podcast,” which focuses on anxiety management.

“Podship Earth,” “The Political Life” and “Energy Policy Now” are podcasts on her list that focus on work-related topics and provide insight and education as she walks.

Robert Plant’s “Digging Deep” and “The Hamilcast” provide entertainment diversity. And a number of health and fitness podcasts are helping her navigate middle age.

“I listen to all of these and more as I travel, walk, meditate and exercise at home, because there are podcasts for all of those activities. I have gained the advice and guidance of trainers, health advisers, doctors, yoga and Pilates experts, dietitians and therapists — all within the walking radius of my home and during a global pandemic.

“I really like ‘Ten Percent Happier,’ with journalist Dan Harris, that focuses on anxiety management. I also recommend ‘Diet Starts Tomorrow,’ a podcast hosted by Betches co-founders Aleen Dreksler and Sami Sage, featuring all things wellness, weight loss, mental health and fitness.

“And finally, while podcasts are not a substitute for tailored professional advice, the range of shows devoted to getting information out to families battling cancer and health crises is amazing.”

Eighth-grade teacher Peggy Dewane-Pope enjoys listening to podcasts while exercising.

“They invigorate me and help me be more open to different ideas,” she said, noting that TED Health is a go-to podcast because the episodes are short — 10 to 30 minutes long — and cover topics ranging from body image shifts to the power and pain of anxiety.

“Listening to ‘The Inaccurate Link Between Body Ideals and Health,’ with Nancy N. Chen brought back memories,” she said. “I remember when body image acceptability shifted from a healthy body, like Marilyn Monroe’s, to a shockingly thin Twiggy in the '60s. I love the shift now to more diverse bodies, skin colors, hair styles and ages. I see people in ads now who reflect the people I work with and teach.”

Jennifer Black is a well-known Kaiser doctor. Until her recent transfer to Kaiser in Portland, Ore., she headed the health system’s local palliative care services.

“Most of my (podcast) choices are about love and relations and living well NOW because, well, I’m a hospice doc. Go figure,” she said, recommending “Where Should We Begin,” which features Dr. Esther Perel, a psychotherapist, who specializes in couples’ therapy, intimacy and eroticism.

“Each podcast is an actual couples’, or friends’ therapy session,” Black explained. Perel “is witty, quick, brilliant, insightful, intuitive.”

Another favorite is “Unlocking Us,” by Brene Brown, a writer and researcher, who specializes in shame and vulnerability.

“She has spent 20 years studying what brings meaning and purpose to our lives,” Black explained, adding Brown “interviews fascinating people in each episode. Willie Nelson and his son were recent guests.”

It’s no surprise that “Write Your Last Chapter” by Dr. Faryal Michaud is another podcast on Black’s favorite list.

“Faryal is a palliative medicine doc, as I am, and also a life coach, who uses her experience with end of life to help others live well NOW. Do not wait,” said Black. “As an example of her work, check out her Aug. 26 episode, which is an excellent interview with a fellow physician (a radiation oncologist) who coaches cancer survivors.”

Dr. Jen Gunter, an OB/GYN physician, created “Body Stuff” with NPR “to dispel medical myths,” said Black. “It’s factual and funny. Her voice drives me a little nuts, but the content is good.”

Stacey Shepard is a big fan of NPR’s “Hidden Brain,” which focuses on studies related to memory, happiness and related topics. Shankar Vedantam uses science and storytelling to reveal the unconscious patterns that drive human behavior, shape our choices and direct our relationships.

“It’s just always cool and fascinating,” she said.

While some could argue one of Jennifer Burger’s favorite podcasts is not strictly “health,” the Cal State Bakersfield professor is a fan of “Dear Sugars,” which tackles a variety of topics, including healthy relationships and healthy habits. Burger compares the podcast to “an advice column by two very smart, well-read writers, who bring on special guests and quote from poetry and literature.”

Local educator Kathryn Mears admits that she has only sampled the tip of the podcast iceberg in her listening.

“There are so many out there now. I haven’t been able to take the time to check more out,” she said. “It’s like going to the library. You need time to browse the aisles.”