- Experts reveal the prevalence, signs and risks of exercise addiction
- "It isn't about vanity at all," one exercise addict says
(CNN)Even if Abby Heugel wanted to stop, she couldn't.
She had to sweat. She had to feel her heart race and her muscles stretch, contract and burn. She had to be in control. She had to exercise.
Heugel, 35, has a history of depression, obsessive-compulsive disorder and exercise addiction, which has left her underweight for a decade, she said. Although she sees a therapist, she said she struggles with her addiction every day.
"I physically feel like I will jump out of my skin if I don't move every couple of hours. Mentally, it's torture," said Heugel, a writer based in Grand Rapids, Michigan.
Heugel has often shared stories about her depression and OCD in her work, in a snarky, tongue-in-cheek way, with dry humor -- but she says she rarely opened up about her exercise addiction.
Many people don't seem to understand how exercising can evolve from a healthy habit to a potentially harmful addiction, she said, and she wants to change that.
"I would define it as part of my anxiety and OCD. I don't over-exercise because I think I'm fat and need to lose weight. In fact, it's the complete opposite. ... If I could have 40 pounds put on my frame tomorrow, I would do it in a heartbeat, which is why so many people are confused," Heugel said.
Heugel said that she also hasn't been photographed in years because she's not comfortable with how she looks right now.
"Why not eat more? I do eat more than a normal person, but it's all very controlled and obsessive as well and not enough to sustain my overactivity. Why not just rest? Because like alcohol or drugs, it's an addiction," she said. "It's what I do when I'm anxious; it's part of my routines. It's a compulsion."
Exercise addiction is not included in the Diagnostic and Statistical Manual of Mental Disorders, the authoritative guide to defining, classifying and diagnosing mental health disorders. The only behavior-associated addiction in the DSM is gambling.
However, a paper that published last month in the British Medical Journal encourages health-care professionals to recognize and understand the risks of exercise addiction.
Symptoms of exercise addiction appear in about 0.3% to 0.5% of the general population worldwide, said Heather Hausenblas, a professor of kinesiology at Jacksonville University in Florida and lead author of the paper.
"It's a small percentage, but ... if you're taking a look at the whole country, it's hundreds of thousands of individuals who have this," Hausenblas said.
"We tend to -- rightfully so -- think of exercise as a really positive thing we need to be doing, and most of us don't exercise enough and aren't getting a hold of the health-related benefits of exercise," she said. "But like with any behavior, we can take it to an extreme."
When exercise is taken to an extreme, Hausenblas said, it can manifest as a secondary addiction, in which it's secondary to an eating disorder and an individual is exercising only to control or maintain their weight. Or exercise addiction may manifest as a primary addiction, in which there is no underlying pathology.
Although men and women are equally at risk for exercise addiction, it more often appears as a primary addiction in men and a secondary addiction in women, according to the paper.
"The research has been slow, but it is growing, clearly showing that there are groups of individuals who engage in too much physical activity to the point where we would classify it as an addiction," Hausenblas said.
'Most don't know what goes on behind the scenes'
For Heugel, the symptoms of primary exercise addiction, as well as OCD and depression, became more apparent in her early 20s.
In 2015, she needed two blood transfusions because she was anemic from over-exercising, she said. Her doctor told her that she had to find a therapist.
Now, Heugel is no longer anemic and frequently visits her therapist, Brendan Kelly, who helps her "sort things out."
"It's a daily or hourly struggle, and combined with depression, it's really tough," Heugel said. "I'm a highly functional individual on paper. I have a great job, a house; people think I'm funny ... but most don't know what goes on behind the scenes."
Although exercise developed into a compulsive disorder for Heugel, Kelly said it's important to remember that exercise can have a positive impact on both mental and physical health for many other patients. A regular exercise routine can even be incorporated into ongoing treatment for certain mental health conditions, said Kelly, co-founder of The Well Being, an outpatient therapy service in Grand Rapids, Michigan.
But for those with exercise addiction, the goal of therapy is to help patients recognize their addictive behavior and reduce extreme exercise routines, according to the new paper.
There is scant research available on the treatment of exercise addiction, but the paper notes that cognitive behavioral therapy is recommended, as with other behavioral addictions.
"Patients may find it beneficial to work with fitness professionals and psychotherapists to design an appropriate training regimen and to re-learn how to use internal sensations, such as pain and fatigue, to differentiate between appropriate versus excessive training and healthy versus unhealthy motivators, such as comparison with others," according to the paper.
Yet when exercise shifts from a seemingly healthy habit to an addiction, the signs and symptoms are often overlooked -- and the shift happens slowly, said Paula Quatromoni, an associate professor and chairwoman of the department of health sciences at Boston University. She is not related to Heugel's case.
"Like an eating disorder, an exercise disorder is a very slippery slope. It usually starts with good intentions: to get fit, to lose a few pounds, to look good for the wedding, to lose the weight after having a baby, to train for a first triathlon," Quatromoni said.
"When the behavior becomes compulsive, it takes over and is never satisfied. It is a driven need to exercise. The need to exercise, to exercise hard and to exercise several times a day becomes more important than almost anything else. More important than being with friends. More important than going to work. More important than getting sleep. More important than eating," she said, adding that the addiction often accompanies other mental health illnesses, like anxiety or OCD.
'I hate how I look and how I am'
The signs and symptoms of exercise addiction include exercising despite illness or injury and having withdrawal symptoms when you can't exercise, such as anxiety, said Hausenblas, author of the new paper.
"It's not the amount of exercise. You can have an elite athlete, and if they have an overuse injury, they're going to take the time off to let their body heal, whereas someone who is exercise-addicted will not be able to or it's going to be extremely difficult for them to be able to do that," Hausenblas said.
"There's an individual that I interviewed that had run a marathon and kept running, because he felt like he still needed to exercise more," she said. "Another individual ended up buying gym memberships, and he said it was getting very expensive for him. He bought three gym memberships because he did not want one gym to realize how much he was exercising. So in the morning, he would go to one gym, in the afternoon another and then in the evening a different one."
The health risks of exercise addiction range from overuse injuries, dehydration and anemia to developing a compromised immune system and even death, especially when paired with an eating disorder, said Boston University's Quatromoni.
"The warning signs are not always visible, certainly not to a health professional who doesn't see the social consequences of the disorder like lack of interpersonal relationships, loneliness, isolation," she said. "As a society and as professionals, we are not used to looking at exercise as 'too much of a good thing' in a way that can negatively affect your health."
"What I wish people understood was that it isn't about vanity at all. I hate how I look and how I am, but it's truly a disease, a combination of several things that culminate in my behavior, and it's a real thing, not an excuse or something we just make up," she said. "It's complicated, and I don't expect anyone who doesn't suffer from it to understand, only to be compassionate of the struggle."