In athletes, a surprising lack of changes in body weight and composition may be explained by decreased level of baseline RMR resulting from the long-term energy deficiency. Moreover, diets implemented during this dietary intervention aimed to provide a sustainable energy balance, thus to avoid weight gain. In athletes, Dueck et al. [31] and Kopp-Woodroffe et al. [32] demonstrated the resumption of menses after approximately 6 months and 9–12 weeks, respectively. Competitive athletes should be counseled that the sustained resumption of menses (involving regular menstrual cycles of 36 days or less occurring

in the period of 3 months or more) may take longer selleckchem than one year, when non-pharmacological therapy is implemented. Arends et al. [33] found that the restoration of regular menstrual cycles in female athletes is possible after increasing the energy value of daily meals contributing to body weight and BMI increase. In the group of 373 female athletes, after five-year non-pharmacological dietary therapy, regular menstrual periods returned in 17.6% subjects. Moreover, in this group, a significant increase in BMI, from 20.8 ± 0.5 kg/m2 to 22.7 ± 0.6 kg/m2 (p < 0.005), as well as in body weight, from 58.0 ± 2.0 kg to 63.3 ± 2.3 kg (p < 0.005), were also observed. However, no information on body composition of the athletes from

the above group were obtained. Dueck et al. [31] showed LH pulsatility accompanied by

the weight gain of approximately 3 kg and a 6% body fat increase. In contrast, Loucks et al. [34, Erastin 35] have suggested that body weight changes are not associated with menstrual disturbances in athletes, probably due to adaptive energy-conserving mechanisms development allowing for the maintenance of body weight despite poor energy availability. Mallinson et al. [25] compared and contrasted responses of two exercising women with amenorrhea of varying duration to an intervention of increased energy intake. This study was very similar to ours due to implementation of a non-pharmacological dietary intervention without reducing the energy expenditure or the intensity and volume of training. In the case study conducted by Mallinson et al. [25], resumption selleck products of menses occurred 23 and 74 days into the intervention for the women with short-term and long-term amenorrhea, respectively. Recovery of regular menses and onset of ovulation coincided closely with increases in energy intake, weight gain and improvements in the metabolic environment. In female athletes, difficulties in the restoration of regular menstrual cycles may result from multiple overlapping causes of such disorders. Bruni et al. [36] reported that inadequate dietary habits, extensive physical activity and stress are key factors differentiating women with menstrual disorders.