Decades ago, before I was born, my mother was a dancer. I have never seen her on stage, but I think I can imagine it in the way that she still walks, toes pointed out and a step so light it is almost as though she is floating. She must have assumed that I’d dance too, but when the teacher told me to suck in my stomach and I started to cry before my lessons, she let me stop without question. If she was disappointed, she didn’t show it.

It wasn’t just ballet that I disliked; throughout my childhood and adolescence, I avoided most physical activity. I closed myself in the office of my school’s newspaper during gym class and stood awkwardly at the periphery during school dances. Meanwhile, my mother spent her free time between school drop-offs and pickups and lunches and play dates at the gym, on the cutting edge of any fitness class trend. Long before the boutique spin studio craze, she told me about how she climbed imaginary hills in the dark on a stationary bike.

One time, I walked into a ballet studio with my mother, and turned to see tears in her eyes as she picked up a toe shoe and traced the ribbon with her finger. I watched, uncertain of how to react. The intensity of her passion and the yearning that came with it mystified me. I didn’t think I would ever connect with that part of her.

So when I finally joined a gym, midway through medical school, it wasn’t because I wanted to sweat. I needed a break from the monotony of memorization, I wanted to meet people, the gym was cool enough to boast a pole-dancing class I’d never take, and the location (just a half-block from a Tasti-D-Lite) seemed to promise me entrance into the “Sex and the City”-themed life I imagined.

The spin studio was in a basement. I signed up for the class on a whim and I didn’t even own bike shoes, so I strapped my sneakers into the pedals and struggled to get the seat at the right height. When the instructor shut off the lights, I could barely make out my body’s form in the mirror. The music blasted. And to my surprise, there in the dark, I found myself moving to the beat. I felt sweat dripping from my forehead down to my arms and onto the floor and I sang and yelled and pumped my fists and it was like a dam had broken and for the first time in my life, strapped into those bike pedals, I felt like I was dancing.

I called my mother as soon as class ended, before I had even taken a shower. I couldn’t wait to tell her. “You really liked it?” she asked, worried that I was just trying to please her. Even though my feet wobbled and the seat was a little too low, I wanted to keep singing and sweating in that dark room every day, forever.

The next time I came home to Miami, my mother and I slowly began the new ritual of going to spin class together. I always chose a bike in the front, as close as possible to the instructor’s contagious energy. My mother preferred the back. From time to time, I would glance over my shoulder and there she was, a few rows behind me, waving a towel over her head or biking with her eyes closed, moving in sync to the music. I don’t think I’d ever seen her so free or so happy.

Spin class was our thing. Even though she lived in Miami and I lived in New York, we called and texted the details of our favorite classes, like who had played Pink’s “Raise Your Glass” or that great remix from “Rent.” I heard about one instructor who brought in a drummer, and another who gave each rider a thimble of Cuban coffee before class started. The sign-ups at her gym went from paper to online before I had taught her how to navigate the internet, and for a few weeks, I was the one who signed her up — right before rounds in the hospital, 26 hours before the class started so she wouldn’t miss her favorite bike. Each time, she thanked me as though I had performed a miracle.

I wonder how many classes we’ve taken together over the years. I think it has to be in the hundreds. I’ve even squeezed in a spin class with my mother right before our drive to the airport, lingering in the studio afterward, browsing through gear we won’t buy while my suitcase waits in the car, neither of us wanting the time to end.

Inevitably, though, it does end, of course. My flight approaches and then it takes off. Time ticks by, months at a stretch between my visits. These days, when I see my mother in Miami, her back hurts and so she sends me to class without her. She waits for me outside.

Back in Boston, where I now live, I go to spin class nearly every morning, before I head to work. There is something sacred in that room, something I never could have anticipated in my years of avoiding exercise. It isn’t just the sweat, or the idea that I’m burning calories. Maybe this is my mother’s gift to me: When the doors close and I’m clipped into that bike and the lights go down and the beat grabs me, everything is so simple. Outside the room, we are all growing older and there is possibility and excitement, but with it, deadlines to meet and decisions to navigate. Yet in there, my only job is to move my body, to time my legs to match the music, to stand when the instructor tells me, to sit, speed up or slow down.

And class after class, week after week, those 45 minutes have become my own. I like to arrive early, so that I can sit outside the studio. I watch people pass me by as I change into my bike shoes, pulling the Velcro straps tight. Then I take my seat in the front row and clip my feet into the pedals. The doors close, the lights dim and I watch my shadow in the mirror and in a way, I dance.