Although I’m not a big fan of the gym, I try to focus on my workout while I’m there, so I don’t make a habit of carrying my phone around with me. But as I walked on a treadmill one day in May 2008, I kept the device propped up on the display panel. I’d had a biopsy for a lump in my breast 3 days earlier and was expecting a call with the results. I knew that when the word came from my doctor’s office, I would either feel enormous relief or face an entirely new and frightening reality. There was no particular reason to expect a breast cancer diagnosis. I’d had some cysts in my breasts a few years earlier, but the biopsy revealed they were benign. I had no family history of cancer and, beyond high blood pressure, had never had any health problems. I was a strong 43-year-old woman who had raised three children and walked three marathons. MORE: 4 Signs Of Breast Cancer That Have Nothing To Do With Feeling A Lump I kept up a steady pace on the treadmill until the doctor called with bad news: The biopsy indicated breast cancer. He said it was treatable and promised to follow up soon with more details. He also warned me against trying to figure out my prognosis online, which would only confuse and alarm me. I knew this already—years before, I’d worked as a surgical trauma and critical care nurse, so I’d learned that this kind of cancer was complicated and highly varied, with many possible treatments. I got off the phone and stood there, thoughts flooding my head: I would have to pick an oncologist and a surgeon. I’d probably have a mastectomy, then chemo, then who knew what. I would have to tell my children, who were 18, 17, and 16 at the time. While fear came in waves and I broke down in tears a few times, I mostly maintained a positive, take-charge attitude. I thought, OK, I can have breast cancer and I can lose my breast, but I can still be here and still have a life, so let’s deal with this. I plunged ahead into whatever came next. I had a mastectomy in July 2008, and that operation and the reconstructive surgery that followed went as well as I could have expected. I took time off from my job in clinical pharmaceutical research after the surgeries but returned to work during chemo. I passed on wearing wigs—they were too hot and itchy and didn’t feel like me, so I wore scarves when it was chilly. MORE: 10 Cancer Symptoms Most People Ignore I tried to find my way back to normal. And normal for me had always meant being fairly active, even when I’d faced another serious life challenge. In my mid-30s, my relationship with my husband started to crumble. I’d believed we had a marriage that was working, but it was becoming clear he no longer agreed. I felt like I needed a healthy outlet—something that would help me cope, physically and mentally, with that rocky stretch. I saw a flyer for a walking marathon to benefit the Leukemia & Lymphoma Society, and I decided to try it. It was an incredible experience, and I found that walking was a great way to feel strong and focus on myself. In 2002, after 16 years of marriage, my husband and I divorced. The breakup shattered me, and it was tough to figure out how to reconfigure my life afterward. I concentrated on taking care of our kids, but I also kept walking. I signed up for another marathon, and training for it helped me deal with that painful episode, giving me long periods of time to clear my head. But fighting cancer was a whole other challenge, one that literally—for a while, at least—separated me from my former life. I wasn’t walking with the intensity I’d had before. After I finished chemo, I received hormone therapy to prevent the cancer from coming back, and one of the side effects is bone pain. Every morning I would roll out of bed feeling much older. I struggled with that but was committed to the drug regimen. I did yoga for a little while and also tried weight lifting and boxing, but my energy continued to drag, and I didn’t feel the same sense of elation I’d felt when I was walking. (Here are 7 incredible results you get from walking 30 minutes a day.) In 2012, with my kids off to college, I moved to Boston for a new job at a different pharmaceutical company. I had a desk job, and over the years I gained more weight than I was happy with. I left my car parked in one spot so I would walk more, but I couldn’t get back to walking recreationally. Then, last summer, my employer allowed me to move back to my childhood home in West Chester, PA, and work remotely so I could live with my 85-year-old mom. In the fall, I connected with a trainer who was developing a 9-week program for a Rodale book, Walk Your Way to Better Health (click here for more on that). She was looking for a group to test it, so I signed up. I loved having an achievable plan, which involved setting aside 15 to 60 minutes every day to walk. It was a revelation to be back in my hometown for the first time since leaving for college. West Chester has a cute little downtown now, with great shops and restaurants. It’s been fun going to the new parks and beautiful trails that have opened since I left. I’m enjoying nature: seeing the sun rise, glimpsing a fox running across a path. I adopted a Bouvier puppy I named Zoey, and I’m out walking with her all the time. MORE: The Best Walking Workouts If You’re Over 40 The best part: I feel better—as good as I’ve felt since before I had cancer. My whole psyche improves when I’ve gone out and done some significant exercise, plus I have more energy. I’ve lost a little more than 8 pounds and shaved 5½ inches from my arms, hips, and waist, which feels really good. My cholesterol and blood pressure are down, too. I know I can count on walking to help me through whatever life hurls at me. Recently, while out with Zoey, I was thinking about the day I got my diagnosis. Even with the fear and anxiety and the urgency to start doing something about it, my first move was never a question. After the call, I walked back into the gym, hopped up on the treadmill, and finished my walk.