SHBG and amenorrhea: In contrast with the vantages of sport activities in decreasing the abdominal fat, blood glucose, lipids and insulin resistance as well as in regulating the menstrual cyclicity, ovulation and fertility due to the lowered testosterone levels and increase of sex hormone binding globulin (SHBG), the intensively exerted agonistic sports may typically produce the ‘female athlete triad’, a syndrome characterized by amenorrhea, osteoporosis and eating disorder as defined by the American College of Sports Medicine [17].