Although scarce , the data available to date suggest that hyper and rogenism , such as that observed in PCOS , may likely be associated with oligomenorrhoea in exercising women , and may not always represent hypothalamic inhibition secondary to an energy deficiency .
To date , the predominant mechanism underlying  menstrual disturbances in exercising women supports an underlying energy deficiency-related aetiology , in which a failure to compensate dietary intake for the energy cost of exercise suppresses reproductive function .
Increasing evidence demonstrates that energy deficiency plays a causal role in the induction of amenorrhoea in  exercising women , and consistent with this mechanism are findings of glucoregulatory perturbations such as low triiodothyronine , reduced insulin secretion and elevated cortisol , growth hormone and ghrelin levels .
The menstrual disturbance that may differ in its energetic characteristics and , perhaps in its and rogenic and ovarian steroid environment , is oligomenorrhoea .
We conducted a systematic review of the literature to begin to underst and whether oligomenorrhoea in  exercising women is a mild sub clinical phenotype of polycystic ovarian syndrome ( PCOS ) in which exercise is conferring beneficial effects in protecting women from the classic PCOS phenotype , or whether oligomenorrhoea is part of the spectrum of menstrual disturbances caused by an energy deficiency that is often reported in exercising women with menstrual disturbances .
Phenotypic spectrum of polycystic ovary syndrome: clinical and biochemical characterization of the three major clinical subgroups.
OBJECTIVE We tested the hypothesis that the three clinical phenotypes of polycystic ovary syndrome ( PCOS ) represent forms of the same metabolic disorder . DESIGN Prospect i ve cohort analysis . SETTING University-based tertiary care . PATIENT(S ) Three-hundred sixteen untreated consecutive women diagnosed as having PCOS . INTERVENTION(S ) None . MAIN OUTCOME MEASURE(S ) Each subject underwent an  evaluation of ovulatory function , body habitus , acne , and hirsutism ; serum free and total testosterone ( T ) , 17-hydroxyprogesterone ( 17-HP ) , and DHEAS ; and fasting plasma glucose and insulin levels . Insulin resistance and beta-cell function were assessed using the homeostatic assessment model equation ( HOMA-IR and HOMA-beta-cell , respectively ) . RESULT ( S ) The Oligo+HA+Hirsutism phenotype was present in 48 % of subjects , Oligo+HA in 29 % , and Oligo+Hirsutism in 23 % . The three phenotypes did not differ in mean body mass index , waist-to-hip ratio , racial composition , degree of oligo-ovulation , prevalence of acne , or family history of hyper and rogenic symptomatology . However , subjects demonstrating the Oligo+HA+Hirsutism phenotype were the youngest and had the greatest degrees of hyper and rogenemia , hyperinsulinemia , and beta-cell function ; patients with the Oligo+Hirsutism phenotype where the oldest and had the mildest degrees of hyper and rogenemia , hyperinsulinemia , and beta-cell function . Subjects with the Oligo+HA phenotype demonstrated intermediate degrees of hyper and rogenemia and metabolic dysfunction . CONCLUSION ( S ) We conclude that the three clinical phenotypes of PCOS do not represent forms of the same metabolic disorder and may be the result of varying degrees of metabolic dysfunction ; greater degrees of beta-cell function and circulating insulin levels favored the development of hirsutism and frank hyper and rogenemia
Although scarce , the data available to date suggest that hyper and rogenism , such as that observed in PCOS , may likely be associated with oligomenorrhoea in exercising women , and may not always represent hypothalamic inhibition secondary to an energy deficiency .
To date , the predominant mechanism underlying  menstrual disturbances in exercising women supports an underlying energy deficiency-related aetiology , in which a failure to compensate dietary intake for the energy cost of exercise suppresses reproductive function .
Increasing evidence demonstrates that energy deficiency plays a causal role in the induction of amenorrhoea in  exercising women , and consistent with this mechanism are findings of glucoregulatory perturbations such as low triiodothyronine , reduced insulin secretion and elevated cortisol , growth hormone and ghrelin levels .
The menstrual disturbance that may differ in its energetic characteristics and , perhaps in its and rogenic and ovarian steroid environment , is oligomenorrhoea .
We conducted a systematic review of the literature to begin to underst and whether oligomenorrhoea in  exercising women is a mild sub clinical phenotype of polycystic ovarian syndrome ( PCOS ) in which exercise is conferring beneficial effects in protecting women from the classic PCOS phenotype , or whether oligomenorrhoea is part of the spectrum of menstrual disturbances caused by an energy deficiency that is often reported in exercising women with menstrual disturbances .