If you’re looking for Denise Sauriol this October 7, she won’t be hard to find. Just stand somewhere along the 26.2-mile course of the Bank of America Chicago Marathon. Keep an eye out for the woman dashing by with a megaphone, encouraging the 190 runners — about half of them first-timers — she’s coaching through the race.

The 50-year-old will complete her 100th marathon, and 24th Chicago one, this year. She was once a type-A runner who focused only on improving her times — until a dramatic accident almost a decade ago changed everything. Now, as a full-time coach and proprietor of a company called Run for Change, she’s helped hundreds of other runners do what they once thought impossible.

“You don’t know what else you have in you. Sometimes you just need someone else to believe in you until you believe it,” says the woman her athletes call the “Marathon Whisperer.” “That’s what I want to do for other people.”

Sauriol began running in fourth grade, when what she calls a lack of hand-eye coordination ruled out other sports. “It always made me feel better after and it’s still my best friend,” she says. Her first marathon, in 1994, came after her sister completed one. “The following year I did, and it just ignited something in me I didn’t even know I had.”

Like any relationship, her affair with running has had its ups and downs. Before long, Sauriol grew obsessed. She’d log 60 to 70 miles per week in relentless pursuit of new personal bests, and beat herself up when she couldn’t reach them.

That all changed in August of 2009. As she rushed to the start line of a half marathon in New York City, Sauriol was hit by a car. Her body shattered the windshield. She broke six vertebrae, wore a back brace for two months, and emerged as the person she calls Denise 2.0. “Months later, once I was mentally and physically stable, I realized there was a reason why I survived in the state I was in,” she says. “I just wanted to give back to running what it had given to me.”

So, she started coaching other runners, with a focus on marathon first-timers and those new to the sport. At first, she did so on the side of her full-time accounting job. Then another tragedy — the sudden death, in 2015, of her 48-year-old cousin Dave Sauriol — inspired her to “de-corporate,” as she calls it, in June of 2016.

Sauriol now spends her days leading Wednesday track sessions and Saturday long runs, running one-on-one with personal-coaching clients, and writing training plans and emails to those she guides virtually. She’s also the official coach for several charity marathon-training programs, including Girls on the Run, the National Psoriasis Foundation, and Chicago Lights, a non-profit linked to Fourth Presbyterian Church.

Talk with Sauriol long enough, and you’ll quickly pick up on the word blends she calls Denise-isms. The day of her accident is now her re-birthday. Marathons should make you feel SCITED, she says, a combination of scared and excited. The biggest gauge of success isn’t finishing times, but EPH, or experiences per hour. And if you’re short on RunSpiration, well, she’d advise you to talk with some of her first-timers.

Take Max Downham, who decided last year — at age 81 — to finally try a marathon. He’d run all his life and always wanted to tackle the distance. Sauriol made the number 26.2 seem less daunting with her calming presence and positive encouragement.

“I’m not the fastest runner around by any means,” he says. “But no matter how moderately I run, I'm not allowed to use the word s-l-o-w around her.” Instead, she reminds him — and all her runners — of how much faster they are than everyone sitting at home on the couch. Sauriol and Downham ran every step of the race together last year; despite his hip pain and warm temperatures, they finished in seven hours and 30 minutes.

Like Downham, Carrie Stern also met Sauriol while training for her first marathon last year with Chicago Lights. “She talks to everybody as of she’d known you forever,” she says. “Each person, regardless of what their story may be, she is able to connect.”

Before the race, Stern recalls, Sauriol hosted a party in a room decorated with motivational sayings and photographs of her runners, with experts like a massage therapist and nutritionist there to dispense last-minute wisdom. And, Sauriol recommended mental tactics for when the going gets tough — such as a gratitude alphabet, thinking of something you’re grateful for that starts with each letter from A to Z, then repeating.

That technique worked for Stern, who finished without injury, as she’d hoped. “I felt strong and proud that I could accomplish this goal around having a toddler, being a teacher, and all these other things in life,” Stern says. “I also felt very lucky that I had all these people cheering me on, this support system.”

The sort of “controlled transformation” that comes with doing hard things is what Sauriol thinks anyone can gain from crossing the finish line. Her new book, Me, You & 26.2: Coach Denise’s Guide to Get YOU TO YOUR First Marathon, features 26 more inspiring stories from new marathon finishers. And, it contains plenty of practical advice for how to make it happen, from buying the right shoes to fueling and hydrating to staying motivated when you’d rather hit the snooze button.

If you’re inspired to try the Chicago Marathon next year, the biggest lesson Sauriol hopes you’ll take is that with commitment, it’s possible. Don’t let the distance intimidate you. Just as you wouldn’t sign up for a class in Mandarin and take the final next week, start where you are and build up, she advises. And she’s glad to help guide you — even if you don’t hire her or train with her team, her book offers two complete 20-week “syllabi” or training plans to choose from based on your current running level.

Though her passion lies in helping others, Sauriol does still have her own running goals, too. She pushes herself to what she feels is her hardest effort at about one-fourth of the marathons she runs, though she no longer aims for specific times. She’s traveled the world to race, completing marathons as far away as Iceland and Antarctica and as prestigious as the Boston Marathon and the Comrades Marathon, a 90-kilometer ultramarathon in South Africa.

But there was never any question she’d return to Chicago for her 100th. “I found myself on that course,” she says. And if strength, community, and fulfillment are what you’re looking for, she just might suggest you look there, too.

Sauriol will hold a free book-launch event from 6 to 8 p.m. Fri., Sept. 28, at Lululemon, 930 N. Rush St.