It’s been called the female athlete triad: Hard-training women who have very little body fat may suffer from low-bone density, menstrual irregularities and disordered eating. When it comes to the latter, many women who train at very high levels simply aren’t eating enough to meet their active body’s needs. In fact, preliminary results from an ongoing study from Penn State University show that up to 50 percent of active women are undernourished enough to have hormonal disruptions that can negatively affect their long-term health (weak bones, compromised fertility) and short-term workout goals (slow results due to a slow metabolism). The scary thing is that most women don’t realize they’re undereating since they’re following a diet that consists of five to six small meals a day. If you’re not seeing the workout results you’re used to, you may be an undereater.