I blame technology. It was my computer that got me to run again — and not just because sitting at it for years without exercising had gotten me into bad shape. On social media, I vicariously followed other people’s fitness successes: an overweight mom who became a marathon runner, a friend who walked and ran off half her body weight, a music critic colleague who tweeted her day’s playlist after each run. Online, I kept seeing articles about the benefits of exercise; if it were an over-the-counter drug, one doctor said, everyone would buy it. And then there was an app: Couch25K (that’s “couch to 5K”), a program that led you from Square 1 to running five kilometers in just eight weeks, which two members of my extended family had used with success. In my supposedly busy life, joining a gym had always seemed like an insurmountable hurdle. But I can always download an app.

Then I met up with one of my oldest friends for breakfast. “I’ve started running,” she said, and maybe that, coming from a lifelong habit of sisterly competition, is what pushed me over the edge and got me actually to start a couple of weeks later.

The beauty of an app is that it removes decision fatigue. It tells you exactly what to do and when to do it, three days a week, starting with running in mere 60-second intervals. And the beauty of running is that it’s solitary — nobody has to know how long you’ve been doing it. Winded? For all that passerby knows, you’ve already run five miles. Or so you tell yourself. I did betray my newness to the sport by my choice of venue. We had recently moved to a new neighborhood, and I didn’t know my way around. So I began by running in the tennis center parking lot.

Motivation at the beginning is not so hard. I was sure that if I just followed what the app said, I was going to be perfectly fit within a few months. After two days, I bought some good running shoes to replace my tennis sneakers (fighting down self-consciousness in the store; after all, they didn’t know I wasn’t a runner and wasn’t really entitled to be there) and those were a motivator, too, bright and springy and sporty-looking. Then there was the setting. The tennis center parking lot is at one side of a sprawling national park that turned out to be interlaced with wooded trails along a rock-strewn river. I ran through ranks of tree trunks, warm beige in the morning sun, rising from a crust of frozen snow, their branches latticed against the pale blue sky.

At the end of the third week, I posted a picture on Instagram hashtagged #morningrun. My close friends immediately took notice. “Have you been hacked?” one commented.

“Wait,” another wrote, “you were the one who was running? From what?”

It took me eight weeks, until the end of the Couch25K program, to realize that, like so many goals throughout one’s life — losing the weight, finding the boyfriend, publishing the book — running five kilometers was going to be the beginning of something, rather than the end. I didn’t even make it to 5K by the end of the eighth week: The final day has you run for 30 minutes without stopping, which is only 5K if you run fast enough. It took me another couple of weeks to hit the 5K mark. Then that felt anticlimactic, so I registered for an actual race in the fall. Feeling empty without the app’s guidance, I discovered there are a wealth of running apps that will chart your distance and pace and create training programs, and downloaded another one.

The hardest thing about starting to run in middle age was not the running itself. The hardest thing was running through my own prejudices and fears. I had always seen exercise as a means to an end, rather than something I might do for its own sake, and it was hard to shake the idea that the perfect body was the ultimate goal, or to shake disappointment when it failed to appear. Nor did running become magically easy to do; it felt hard most days, and I remained dismayingly slow.

Fear held me back like mud — fear I was doing it wrong, fear I was going to injure myself and have to stop (something reinforced in me by the many friends who told me they were former runners until they had blown out their knees, or developed arthritis). I began having shooting pains down the back of one leg, and worried that my running career was over until Facebook, probably triggered by my repeated googling of “hip pain,” popped up an article about the piriformis, a small muscle in the pelvic area, that exactly described all my symptoms as well as some stretching exercises that, within a few weeks, alleviated them. I was afraid of being cold, until I learned the exhilaration of going out in 30-degree weather and, rather than fighting it, coexisted with it, working up body heat inside the insulated running jacket that had replaced my pink sweatshirt, breath escaping in white puffs. I finally ran my first official 5K race, in the pouring rain, and finished side by side with another middle-aged woman. That felt anticlimactic, too, so I signed up for another.

The benefits were not the ones I had expected, either. As a competitive person who has always measured achievement on a large scale and wants quick results, it took me a long time to realize that I was more focused, sleeping better and slightly less stressed. Then there was the pleasure of uninterrupted listening to music and audiobooks, finding that some pieces of music grew even more vivid when printed into my mind by the pounding of my feet. I got extra adrenaline, listening to Dora Pejacevic’s Symphony in f-sharp minor, from my indignation that this composer is so unknown; David Lang’s “The Day,” with a litany of people’s memories of personal milestones, became a series of affirmations; and I learned the “Hamilton” soundtrack by heart. I hadn’t thought about how my running would affect my family — how my husband, happy to see me joining him in regular exercise, would cheer me on, how our 7-year-old son would want to go running with me, in 40-second bursts, and give me tips to make me faster. It didn’t occur to me that running while traveling would show me places I never otherwise would have seen, like the panoramic views over Prague from a hilltop park. And on the most superficial level, I enjoyed, for the first time in my life, buying athletic gear and actually using it.

I’ve read a lot of these stories, and I know how they’re supposed to end: with me running a marathon, or getting faster, or going down several clothing sizes. But this is not a story of great athletic achievement. I haven’t yet run more than four miles at a stretch, or even averaged that 10-minute mile. Here’s what I did achieve: I did lose 15 pounds. I did run four 5K races, each a bit faster than the last. I did run an average of three times a week, through vacations and work trips, heat and rain and snow, all year long. And after a lifetime of seeing my body as something I had to fight, I feel, for the first time, that it and I are working together. It’s been more than a year now, and I’m still running.