Female athletes low weight helps them to make them fast runners. However, this can be harmful. Recent studies showed evidence regarding this fact. According to a research, done at the Ohio State University Wexner Medical Center, women runners who have BMI lower than 19, were more at the risk of stress fractures. With more risk, these athletes also recover lately as compared to other athletes. The low mass index or low body weight is the biggest reason for fractures. Because, when the runners experience constant pounding on hard surfaces, the leg bone gets weak due to without sufficient lean muscle mass for dissipation of impact forces. Further, a low body mass index is known to cause reduced muscle mass. Due to reduced muscle mass, the shock of running absorbed nowhere except than into the bones.

Scientists also studied the injuries of  Division I college athletes by the Kaeding-Miller classification system.  The scientists formulated this system with the help of other sports medicine experts. This system is different as during representation of injuries on a scale of 1 – 5, the system not only examined patient's symptoms but also other factors such as bone scan, MRI findings, X-ray results and computed tomography (CT) images. The women with BMI of 19, took 13 weeks to recover and the women who had a lower BMI than 19, took more than 17 weeks to recover. The analysis also found that about 25 to 50 % of runners suffered from at least one stress fracture during their career. However, this risk was higher among female runners.

According to scientists, it is crucial for women to know their BMI and effort to maintain that. They also recommended resistance training in their training regimen for lower leg strengthening to prohibit injury. According to scientists the body mass index, a women athlete should maintain is 20-24.