ADIPOQ and amenorrhea: Generally, Adiponectin levels in athletes are high, and they are stable under intense training conditions and low energy states (Jürimäe, 2010); in a cross-sectional study performed on adolescent girls comparing the effects of neuroendocrine factors, such as peptide YY and Adiponectin, on amenorrhea endurance athletes, on eumenorrheic endurance athletes, both under lower energy availability, and on eumenorrheic non-athletes, Russell et al. (2010) found that high peptide YY levels, but not Adiponectin, was a predictor of hypogonadism and impaired bone metabolism in amenorrhea athletes.