Not all the studies that investigated all the conditions in the triad , but the authors concluded that it seemed that athletes were in more severe stage of this disorder .
Luteinizing hormone pulsatility is disrupted at a threshold of energy availability in regularly menstruating women.
To investigate the dependence of LH pulsatility on energy availability ( dietary energy intake minus exercise energy expenditure ) , we measured LH pulsatility after manipulating the energy availability of 29 regularly menstruating , habitually sedentary , young women of normal body composition for 5 d in the early follicular phase . Subjects expended 15 kcal/kg of lean body mass ( LBM ) per day in supervised exercise at 70 % of aerobic capacity while consuming a clinical dietary product to set energy availability at 45 and either 10 , 20 , or 30 kcal/kg LBM.d in two r and omized trials separated by at least 2 months . Blood was sample d daily during treatments and at 10-min intervals for the next 24 h. Sample s were assayed for LH , FSH , estradiol ( E2 ) , glucose , beta-hydroxybutyrate , insulin , cortisol , GH , IGF-I , IGF-I binding protein (IGFBP)-1 , IGFBP-3 , leptin , and T3 . LH pulsatility was unaffected by an energy availability of 30 kcal/kg LBM.d ( P > 0.3 ) , but below this threshold LH pulse frequency decreased , whereas LH pulse amplitude increased ( all P < 0.04 ) . This disruption was more extreme in women with short luteal phases ( P < 0.01 ) . These incremental effects most closely resembled the effects of energy availability on plasma glucose , beta-hydroxybutyrate , GH , and cortisol and contrasted with the dependencies displayed by the other metabolic hormones ( simultaneously P < 0.05 ) . These results demonstrate that LH pulsatility is disrupted only below a threshold of energy availability deep into negative energy balance and suggest priorities for future investigations into the mechanism that mediates the nonlinear dependence of LH pulsatility on energy availability
Not all the studies that investigated all the conditions in the triad , but the authors concluded that it seemed that athletes were in more severe stage of this disorder .