(WRC) -- Obsessive exercise can interfere with work and relationships, and even cause serious injury.
Chris Lear, 53, admits he never was a runner, but when he decided to join a racing series last year, he said the thrill of competition became addictive.
"Once you started winning, it's just very contagious," Lear said.
He started training harder, running longer distances and adding boot camp classes. It took a toll on his body.
"I just hit a point where I couldn't walk anymore," Lear said.
Physical therapist Scott Epsley said he's seeing more and more patients like Lear, who are over exercising and taking their workouts to dangerous extremes.
"It's very common in runners in particular to see this over exercising mentality. There seems to be that psychological, that type A personality," Epsley said.
The number of yoga practitioners has exploded, from four to 20-million in the last decade.
"They're afraid they're going to be fat, fear of losing control. Fear of losing structure in their day to day life, not staying in shape, not staying desirable," said Dr. Antonia Baum, a psychiatrist.
Dr. Baum said over exercisers are often similar to people with eating disorders. They use exercise as a way to control their lives or as an escape.
It became a problem when it gets in the way of social activities or relationships.
"Unfortunately, the way most people know is because they start to get pain," Epsley said.
Bone stress, shin splints and tendonitis are common diagnosis. They also may feel extreme fatigue and joint stiffness.
If you feel pain, see your doctor as soon as possible.