Can your workouts mess with your period?

Suddenly without a cycle? Your fitness routine might be to blame.

You don't have to be a world-class athlete to be at risk for female athlete triad, a syndrome brought on by taking healthy habits to the extreme. The condition is named for its diagnostic trifecta: inadequate calorie consumption, shrinking bone mineral density, and three or more missed periods in a row.

Experts say the number of sufferers has skyrocketed in the years since Title IX ushered in a new generation of fitness-minded females.

What's happening? Not getting enough fuel for your workouts triggers a domino effect in the brain that halts menstruation and puts you at risk for osteoporosis, which can lead to bone fractures.

If your absent periods are accompanied by fatigue, fuzzy thinking, and a faltering workout performance, use an app like MyFitnessPal to make sure your exercise output isn't far exceeding your food intake—or see a nutritionist for help with meal planning. If symptoms still linger after that, contact your M.D.