Cycling Sistas founder Catherine Serio received the scariest news of her life while sitting on her bike.

In the midst of the 2009 “Ride Idaho’’ bike tour, the Boise woman pulled over to the side of the road and took a call from her doctor.

“I started the ride not knowing I had cancer,” Serio recalls. “And just like that, I had two malignant tumors. I got off the bike right then and got ready to begin aggressive treatment.”

The treatment helped Serio survive her battle with breast cancer. But her healing wasn’t complete until she was able to get back on her bike.

“I really wanted to get back out there, even if I couldn’t ride like I could before my diagnosis,” Serio said.

“Mary Biddle-Newberry at the Boise YMCA created a customized program for me to work my way back at my own pace. That made me think how wonderful it would be to start a club for cancer survivors, somewhere women could support one another as we rebuilt our strength and confidence.”

Thus, Cycling Sistas was born.

SMALL BEGINNINGS

The Cycling Sistas began with Serio and a small handful of riders. The club bikes on road courses and in the Boise Foothills during the summer and trains at the YMCA during the winter using computrainers — stationary machines that hold each person’s bike, allowing the group to ride the same virtual course together, each rider at her own pace.

Early on, the club received sponsorship from the YMCA, Livestrong and Saint Alphonsus Regional Medical Center. Soon, the Sistas were growing in numbers.

“I joined right out of chemotherapy,” said Janice Neri, an ovarian cancer survivor. “It’s been such an important part of my ongoing recovery. I was very afraid of what my body could and couldn’t do after treatment.

“Having people who understand where I’ve been both physically and emotionally — and who can see not only my weaknesses, but also my strengths — has been a huge support.”

CLUB OF SURVIVORS

In two short years, Cycling Sistas has grown to include about 20 Treasure Valley women.

The group meets two to three times per week to ride and train. Current members, including Donna Taggart, stress that new riders of all abilities are welcome.

“We have members who are at many different levels of recovery, athletic ability and experience,” said Taggart, who overcame Hodgkin’s Lymphoma. “We aren’t a competitive group; we are a group of survivors. And thanks to the computrainers, we can all train together at our own pace.”

Joining Cycling Sistas has been a powerful experience for Carmel Crock, a breast cancer survivor who had no prior experience on a road bike.

“The extent of my riding was on a cruiser bike,” Crock said. “But this group has changed my life. It’s given me friendship, laughter and shoulders to cry on. I’ve been on a mission to recruit more people ever since I started, because people need to do this. Women need this.”

One of Crock’s recruits is Susan Bistline, whose battle with brain cancer left her bedridden for months.

Slowly but surely, she’s regained her strength through the Sistas.

“I was afraid of getting back into the world,” Bistline said. “But I wanted to achieve some level of fitness. I ran into Carmel, and I’ve had a connection with all of these women since I met them. It’s provided me with a growing strength.”

BONDS BEYOND CANCER

Surviving cancer is the common thread that connects each member of the Cycling Sistas.

But as new members join the club, many of the women find they share many similarities not related to cancer, or even to cycling.

“We all have this cancer bond, but to me what makes the group special is that we have such unique individuals,” breast cancer survivor Cecile McMonigle said. “It’s such a pleasure to share camaraderie with so many wonderful people who you never would have known otherwise.”

Adds Taggart: “We don’t always talk about cancer. It’s moved beyond that.”

The Sistas — easy to spot in their yellow, red and pink uniforms as they pedal together down Hill Road or through Barber Park — instead focus on transitioning back to everyday life.

“The medical system treats cancer,” Serio said. “But Cycling Sistas picks up where treatment leaves off. Women need support through the healing process, and who better to do that with than people who have been on the same journey?”

Overcoming cancer is a long and often frightening challenge. Continuing treatment, medical checkups and scary phone calls are a reality for each member of the Cycling Sistas, along with the countless thousands whose lives have been touched by a relentless disease.

But Serio and her Cycling Sistas draw comfort and strength from their fellowship. No matter what happens next on the trail of life, the Sistas know they won’t have to ride alone.

“It’s become an addiction,” breast cancer survivor Cheryl Imlach said. “When you’re in treatment, you feel like you have no control over your life.

“The beautiful thing about a bicycle is the freedom it gives you, the ability to control where you’re going.”