“That can’t be good,” I remember thinking, as my knees buckled beneath me and I struggled to pull myself back to standing, clinging to the kitchen counter. I was making (okay, microwaving) dinner in my New York City apartment and had dropped my fork. I bent down to pick it up, and my knees seemed to stop working.

I had gone for a run that morning—and every single morning before that, plus a spin or kickboxing class in the evenings, for about three months. Things had started to hurt, sure, but this was different. This, I could tell, was my body’s way of telling me to stop, Alison, seriously. This was my wakeup call. My body was beat, and after weeks without a rest day, I finally accepted it.

At some point, my daily runs had gone from being a fun hobby to an obsession to a compulsion.

It’s clear to me now that I was addicted to working out. I think I sort of knew it at the time, but I refused to accept it or do anything about it. I recognized that, at some point, my daily runs had gone from being a fun hobby to an obsession to a compulsion. It’s not like I was addicted to pills or drugs or alcohol. I just wanted—needed—to break a sweat every day. There couldn’t possibly be any harm in that, right?

Wrong. Exercise addiction is very real, and can be damaging both physically and mentally. Though I’m proud to report those days are behind me, exercise addiction is becoming increasingly prominent.

Here’s the lowdown on this not-so-easily-defined disease.

Exercise addiction can be difficult to diagnose

“Frequent physical activity is often seen as a desirable habit,” says Dr. Leah Lagos, a clinical and sport psychologist in New York City. “So most exercise addicts don’t see anything wrong with their behavior, and often don’t report it.” Plus, the American Psychiatric Association (APA) doesn’t officially recognize exercise addiction as a diagnosis, which means there are no specific criteria to use for someone who may be suffering from it.

“We see exercise as such a good thing for us, but as with anything, people can take it to an extreme.” —Heather Hausenblas, PhD, co-author of The Truth About Exercise Addiction

That’s why Heather Hausenblas, PhD, a professor of kinesiology at Jacksonville University and co-author of The Truth About Exercise Addiction, has dedicated her career to studying exercise addiction.

“We see exercise as such a good thing for us, but as with anything, people can take it to an extreme,” she says. “If it becomes all-consuming, it can have negative consequences.” Hausenblas defines exercise addiction as “excessive physical exercise that’s compulsive and results in negative health consequences physically, psychologically, and socially.” She created the Exercise Dependence Scale, and says people exhibiting three or more of its indicators—ranging from symptoms of withdrawal and lack of control to continuing to exercise through significant pain—may be facing exercise addiction. If you feel like this applies to you, consider seeking professional medical advice from a doctor or therapist.

The primary factor to look for is the motivation behind exercising

An exercise addict needs physical activity to feel normal, and will experience withdrawal symptoms, such as anxiety or depression, if he or she skips a workout session, says Lagos. “An individual who suffers from this addiction will often work out despite illness or injury, feeling unable to stop and allow for rest and recovery,” she says. If an exercise addict isn’t able to work out, he or she will probably feel anxious, depressed, or stressed.

“The withdrawal effects are a sure sign of exercise addiction,” adds Hausenblas, “and they’re very debilitating. If you’re the average exerciser and you have a meeting run late or something comes up with a family member and you have to miss your workout, you may feel a little guilty, but it won’t affect your day too much beyond that. For an addict, it’ll seriously affect them. They’re often so rigid and so structured that they can’t miss a workout, or they have a constant need to do a little bit more.”

Hausenblas says a telltale sign for spotting exercise addiction is when a person gets an overuse injury—which she says is common—and the doctor says to take a month off. “The average person is okay with that,” she says. “But somebody who’s addicted won’t accept it. He or she will exercise through the pain, or switch activities—like a runner will get on the elliptical to avoid stopping exercise altogether.” Though the body might be in pain or sick, the person will continue trying to perform at maximum intensity.

Being diagnosed doesn’t mean the end of your fitness routine

Exercising compulsively almost always leads to overuse injuries, Hausenblas says. “The body can only take so much before it breaks down,” she adds. It comes with a host of mental consequences, too. “The need to exercise begins to interfere with work or school, personal relationships, and a social life,” says Lagos. “A person who is compulsive about exercise, for instance, may spend more than an hour exercising even if the intent was a 30-minute workout and, as a result, may miss or arrive late to an important work or social event.”

“There’s a fine line between competitive training and damaging, compulsive behavior.” —Dr. Leah Lagos, clinical and sport psychologist

So does that mean your marathon-running friend must be an exercise addict? No. There’s a difference between training for a marathon—where a 20-mile training run is par for the very long course—and needing to run every single day. “Given that so many fitness-loving women run marathons or double up on spin classes for fun, it can be tricky to determine if you’re just another health nut or a dangerously fixated one,” says Lagos. “There’s a fine line between competitive training and damaging, compulsive behavior.”

The first step, Lagos says, is identifying the why behind all that working out. “If exercise dependence is tough to spot, it can be even harder to admit,” says Lagos. “Denying or downplaying the time spent exercising or obsessing about workouts is a common warning sign.” But treatment can be tough. Unlike with alcohol addiction or a drug addiction, abstinence isn’t necessarily the best form of treatment, particularly in the long-term, since exercise has lots of healthy benefits: It can help improve your eye and brain health, make you happier, prevent depression, and add years to your life, among other positive side effects. Though antidepressants and cognitive behavioral therapy can be helpful for some, the key, experts say, is developing a healthy and balanced relationship with exercise.

“You don’t want people to give up exercising altogether,” says Hausenblas. “It’s a good thing if it’s done the right amount, so you don’t want to say, ‘Don’t exercise.’ But you have to re-train the person’s thought process about what’s an acceptable amount of exercise, and that takes time. And even then, like with any type of addiction, maintaining that balance can be a struggle. It’s not something that just tends to go away.”

Today, I’m grateful to have developed what I consider to be a happy, healthy relationship with my body and with exercise. I no longer run until my legs feel numb and my shins sting, and I don’t feel the need to double up on daily workouts. I used to love having to hobble down a flight of stairs the day after a long run. To me, that was my runner’s high—it meant I’d “really gone for it.” But now I know my body isn’t supposed to be in a constantly achy state.

While my fork-dropping moment was my wakeup call, my mindset and habits didn’t change overnight. It took a while. The main thing that helped was getting a running coach. Once I started working one-on-one with a trained professional, I had a plan. He told me when to run, how much to run, how fast to run, and, most importantly, when not to run. He helped me see the value in rest days and in giving my body time to recover. By building rest days into my training plan, I learned to respect them as part of the process. Resting was training. (I even started looking forward to days off, I swear!)

I unfollowed strangers and friends alike whose behaviors triggered me into thinking I should be doing more, resting less, and doubling up daily.

I also took a serious look at my online habits. I stopped following people whose habits resembled the ones I was trying to overcome. I unfollowed strangers and friends alike (it’s okay, we’re still friends!) whose behaviors triggered me into thinking I should be doing more, resting less, and doubling up daily. I stopped taking classes with fitness instructors who preached about “earning summer bodies in the winter” or “burning off weekend indulgences.” I surrounded myself with everything positive, and nothing that—even if it was no fault of their own—could send me back in to my old patterns.

I also—a while later—talked about and admitted what I had been going through, both on my blog and to my boyfriend. Brian, now my husband, became my source of accountability. When Sunday rolled around and I said I was going to take a day off but then found myself slipping into my running shoes, he made me take them off. He gave me the tough love I wasn’t always strong enough to give myself. And eventually, it all fell into place.

Nothing on my body hurts right now. I choose workouts that feel good and that energize me—not ones that beat me up and leave me feeling ragged. I respect my body and, in turn, it’s been pretty good to me.

Here’s how often to run in order to keep your body happy and your training top-notch. And proper recovery is important, but so is pre-hab. Here’s why.