Two weeks ago, I woke up aching from head to toe, as though I were coming down with the flu or had just run a full marathon the day before. But I didn’t have the flu and I definitely hadn’t run a marathon.

Instead, I had spent a half hour the prior evening swimming laps in the local pool. It was the first time in nearly a year that I’d gone swimming. After I was finished, I felt fabulous—both recharged and relaxed at the same time. But the next day it was clear I had overdone it.

Since being diagnosed a few years ago with fibromyalgia, a disorder characterized by musculoskeletal pain, fatigue, sleep, and memory and mood issues, exercise has become especially fraught for me.

Sitting in a chair—no matter how ergonomically advanced—for more than an hour or so straight can send my back into severe spasms and set off a ripple effect of pain that eventually engulfs my entire body.

Before fibromyalgia, it was not unusual for me to leave my apartment on a whim to take a five-mile walk. In the winter, I often donned snowshoes and cross country skis to traipse the New England trails around my home. I loved to hike and rock scramble up steep mountains. I biked for hours on the tree-lined path that ran behind my building.

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I might not be that active these days, but stagnancy is just as bad for my body (if not worse) than overdoing any exercise. Sitting in a chair—no matter how ergonomically advanced—for more than an hour or so straight can send my back into severe spasms and set off a ripple effect of pain that eventually engulfs my entire body.

Standing still in lines or crowds for more than 20 minutes causes shooting pains in my legs for the rest of day and into the night, keeping me awake at all hours. Even lying down usually does not offer me the pain relief most people would expect. Instead, my body feels its best when (and seems to benefit the most after) it has been engaged in low-impact mobility.

My diagnosis meant I had to educate myself on how to stay in shape without aggravating my condition. But this was a fine line that I had trouble seeing and often crossed unwittingly, especially as my body’s pain levels tend to fluctuate dramatically from day to day.

In my search for some solutions, I recently enrolled in an intensive eight-week rehabilitation program for people with chronic pain. The program emphasizes re-conditioning; it teaches us how to exercise and complete daily tasks in ways that reduce pain. In the program, a team of physical and occupational therapists work collaboratively to modify my weekly exercise regimens in ways that engage me in a level of activity I need to become stronger and more resilient, all the while trying to avoid the dreaded flare-ups.

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What I’ve learned: Quality over quantity is key when it comes to exercise. As a result, I am learning to be more present in my more fragile body. This means understanding and abiding by my physical limitations, while also staying committed to remaining fit and healthy.

What I’ve learned: Quality over quantity is key when it comes to exercise. As a result, I am learning to be more present in my more fragile body.

When I returned to the pool last week, I began applying what I learned. At first, I took my time treading water for a few minutes. When I progressed to doing laps, I swam much more slowly and mindfully, favoring comfort over speed. I took breaks and deep breaths often, gently stretching my legs beneath me between each lap before setting off again.

When my arms began to ache or tingle, I switched to using the boogie boards the club offered and simply kicked my legs gently behind me to get to where I wanted to go. I repeatedly reminded myself that I was not in any rush or race. And when I woke up the following morning, I was not besieged by body-wide aches that made me regret exercising the night before.

Likewise, when I go for one of my afternoon walks now—which are usually only a mile or two as opposed to five—I incorporate a similar tactic. I pay attention to how my body moves and where it hurts, adapting my movements as needed to accommodate pain or tension. I take breaks as often as I need to.

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I occasionally walk with ankle braces and a cane because it relieves pressure on my aching joints and overactive nerves. I also apply methods for preventing pain before and after I exercise, including gentle stretches, massaging tight trigger points with tennis balls, and icing the sore spots on my body.

With time and dedication, I hope to build up my strength and endurance so I can add more laps and miles to my routine, but in a way that doesn’t make my pain worse.

I’m determined to maintain a quality of life that includes me being physically active on a regular basis. If that means modifying my routines, using assistive devices, and even ultimately accepting that I may not always be able to accomplish all of the things I did before my diagnosis, then I’m willing to do it. Though it may seem like a lot of work, my body is worth the effort.