What do you mean I can’t run the stairs anymore?” I asked, confused. The girl with the clipboard shrugged: “I guess the neighbors complained and…” Before she could finish, I set out to find someone superior—someone with a headset or a walkie-talkie, preferably male. They can’t do this to me, I thought to myself. They just can’t.

It was only the second day of filming on the then yet-to-be-named reality show Stylista, and even though I knew it wasn’t in my best interest to let my high-maintenance flag fly so soon, given the circumstances, I had no choice. Before I’d arrived in New York City, even before I’d signed the confidentiality agreement, I’d inquired twice—once each of Casting and of Production—whether I’d be able to exercise during the shoot, scheduled to last more than four weeks. Both informed me, in writing, that it wouldn’t be a problem. But on day one, not only had gym access “fallen through,” but it was also too late to rent machines for the cast apartment, and, because cameras had to be on us at all times, running outside couldn’t be accommodated.

And now, apparently, no stairwell climbing, either. Later that night, I slipped away from the common room where the other 10 contestants were snacking and socializing and locked myself in the upstairs bathroom. There, for the next few hours, I sat on the floor having an emotional breakdown as quietly (so as not to rouse cameraman attention) as I could manage.

At 5’7” and 127 pounds, I neither look nor am, according to my doctor, physically unhealthy. For the past 11 of my 29 years, however, maintaining my weight through a meticulous, real-time tabulation of calories consumed and burned has been my modus operandi. Eating and exercising are, for me, a single, fused activity; there is never one without the other, and more specifically, never an adjustment to one without an equal and opposite readjustment to the other. Just as it did in high school and college, where I was a disciplined rower, my social schedule revolves around my daily exercise, which is always at night, always just before bed. If a 7:30 p.m. dinner is pushed back to 9, I find a reason to cancel. If I can’t, I hit the gym as soon as my food is digested, sometimes as late as four in the morning.

Until Stylista, I hadn’t gone two consecutive days without rigorous exercise since I joined the swim team in the sixth grade. I worked out regardless of illness, injury, heartbreak, vacation, or work deadlines. Exercise might not have always been convenient, but it had never been unavailable- until now. Compounding the problem was that before filming began, I had just come off 18 straight months of training for four back-to-back marathons.

I could be addicted, literally. Tufts University’s Robin Kanarek, PhD, lead author of a study published last August in Behavioral Neuroscience, found that intense exercise triggers the release of neurotransmitters in the same way many addictive drugs do, resulting in a similar, albeit natural, chemical high.

On the floor in that rented, reality-show bathroom, crying, convinced that after only 24 hours without exercise, I could already feel my muscles atrophying-even contemplating quitting the show-I realized for the first time that my relationship with exercise wasn’t just disciplined-it was destructive. To get through the month, I dealt with the situation the only way I knew how: decreased calories. There was concern on-set over my noticeable weight loss, but I told everyone it was temporary, and once I could run again, I’d trade my one-per-day Clif Bar cut into thirds for more substantial meals.

After the show, back at home in DC, where image isn’t at the forefront, most of the people in my life, even those who loved me and whose lives had been inconvenienced for years by my behaviors, told me I was fine. “I know 10 people right now who do what you do and they don”‘t eat gummi bears,” a friend once said to me, half joking. “You exercise a lot,” another said; “half of America should be so lucky as to come down with that disorder.” Rationalizing that my experience on Stylista wasn’t real life but life in a vacuum, one in which I would never find myself again, I threw myself into an even more regimented routine. I feared what not exercising would do to my body, but more than that, I didn’t want to find out what a larger body would do to people’s perception of me. I know overweight women are judged, because I do it every single day. So do many of my friends. So does the media. Sometimes I fight it, but there is something deep inside me that has always associated an imperfect figure with weakness.

It was only a few months ago, well after I’d moved to New York and begun my tenure as a junior editor at ELLE (my prize for winning Stylista) that something changed. One day, in preparation for another article, I happened across a 2008 study by researchers at the renowned Wickenburg, Arizona, eating disorder treatment facility Remuda Ranch that reported that women 40 and over were one of their fastest growing patient groups. Reading that, knowing my thirtieth birthday was only months away, and having recently become an aunt to my brother’s daughter, I realized I neither wanted nor could afford to continue being stuck in the college-girl eating disorder rut. I needed to grow up.

This isn’t the first time I’ve taken a healthy behavior to an unhealthy extreme. Between sixth and twelfth grade, I struggled with the kind of perfectionism most parents, in jest, pray their child develops: At a very young age, I got it in my head that I wanted to be just like Brooke Shields. I didn’t covet her movie career, her beauty-no, I wanted to be the girl who went to Princeton. By high school, my focus had graduated to obsession: I calculated to the tenth of a percentage my grade in every class every single day, cried to the point of hyperventilation if I’d misjudged how I’d done on an assignment, and ultimately, after I’d lost my perfect GPA, came very close on two occasions to committing suicide.

Juliet Zuercher, RD, a former eating disorder specialist at Remuda Ranch, who is now in private practice in Phoenix, Arizona, wasn’t surprised to hear about my past. “People who develop a compulsive exercise disorder often exhibit compulsions in other parts of their lives,” she said. “Plus, you picked two very similar things [in] grades and exercise both elicit praise more than concern.”

Since the issues I had with grade perfectionism worked out over time-a neat way of saying that, through a divine college admissions intervention, I did not attend Princeton but rather Brown, a school whose curriculum was created with a “study to learn, not to get the grade” intention- wouldn’t my issues with exercise resolve in a similar fashion? “Absolutely not,” Zuercher said. “Right now, you’re enslaved by a compulsion to exercise. You can’t lead a normal life, it’s affecting every relationship you have, and from what you’ve told me, it brought you pretty close to ruining the opportunity that got you the job you have today.”

Ashley Borden, an L.A.-based trainer, author (2008’s Your Perfect Fit), and a former anorexic, bulimic, and exercise addict, agrees that “to move strictly for calorie burning as opposed to exercising for health and enjoyment is a problem.” Okay, fine, in theory that may be true, but what is the alternative? I now work in a city where it seems the average woman is two thirds the size of her Midwestern counterpart and in an industry that, according to the Academy for Eating Disorders, hasn’t met the Center for Disease Control’s standard for “underweight,” even for its youngest models. “You need therapy 100 percent,” Zuercher told me. “But you also need to decide what you value most in life. Is it your physical appearance? Is it peace of mind? Is it being comfortable enough with yourself to order whatever you want off the menu and not punish yourself afterward?” From her tone of voice, I knew she didn’t think there was one right answer, but in reality, since I’d called her looking for help, really, there was.

Therapy, in the couch tell-all sense, was too much-at least right away. In my family, we talk, but we do first and foremost. I set incremental goals, even whipping up an Excel spreadsheet to document my progress (setting the treadmill to clock distance, not calories, for example), hoping small successes, over time, would translate into a Thanksgiving holiday without twice-a-day trips to the gym. One step, still the most difficult to abide, was to stop looking at nutrition labels and calorie-counting websites. Granted, I already knew the calories in a serving of, well, anything, but the practice of successfully not doing something I’d done a dozen times a day for a decade was liberating. Even empowering, as I discovered when I spent an entire weekend with my niece, never once-not even when we sat down to eat North Carolina barbecue- stopping to consider the consequence of the hush puppies we shared. The second step was eliminating my daily food journal. Since I was no longer that lightweight rower on whose willpower seven other athletes relied, it didn’t make sense for me to continue a practice most often used with individuals trying to lose weight, who psychologically require seeing on paper how much and exactly where their diet needs improvement. Given how long I’d nurtured these two habits, I was surprised at how relatively easily I was able to give them up. Though I may slip and look at a label now and then, I can honestly say I don’t judge-the food or those who choose to eat it-with the same superiority I once did. And the food journal? Haven’t written an entry since last June, and it’s been enormously freeing. But my obsessive compulsion about exercise has always been the bigger demon.

Zuercher and Borden tell me I need to adopt a similar attitude toward exercise. No more marathons (they’re “the perfect cover for exercise addicts,” Borden says), no more late nights at the gym, no more feeding into this overachieving, hyperdisciplined persona I’ve imposed on myself since before I understood the consequences of that kind of self control. Zuercher says I have two choices: I can either accept my body’s natural weight set point, or I can continue fighting every night in the gym to maintain the one I’m currently at. There is no in between, not with the way my mind is wired. If, after treatment, my body settles at 135 or 140 or some other number I’m not used to, I have to be willing, she tells me, to accept it. I hear these words, and I look down at my legs and arms, I look out my office door and see a steady stream of fashion’s finest-and thinnest. In that moment, which lasted long enough for Zuercher to ask if I was still on the line, I knew she was right. And I also knew my answer to her question-about what I value most in life-was the right one. But just barely.

By Johanna Cox