Nutritional composition in different training stages in young female athletes (swimming) and association with leptin, IGF-1 and estradiol.

Objectives: To investigate the interaction of serum leptin, IGF-1, estradiol and cortisol in salvia as well as IL-6 with nutritional composition in female athletes (swimming) according to the training protocol (competition (C), sprint (S), recreation (R), endurance (E)).

Design/methods: In 23 young (10-19 years old) female athletes (Bavarian swimming competition) in different training stages nutritional protocols were evaluated using standardized questionnaires. Body composition was measured by using analysis of bioimpedance. Estradiol, IGF-1, leptin and IL-6 in serum were measured by ELISA. To obtain circadian profiles of cortisol salvia probes were sampled at 4 h intervals and cortisol in saliva was measured.

Results: Daily intake of kilocalories varied significantly and was highest during R with the highest percentage of nutritional fat intake (37.3%) when compared to C (28.1%, p=0.001). BMI was associated with leptin in all training stages and IL-6 in R, C and E. Leptin, IGF-1 and cortisol in salvia were dependent on training stages while serum levels of estradiol were not. Nutritional fat intake (p=0.07 in R) as well as serum levels of IGF-1 (p=0.014 in E) were significantly associated with estradiol but not with serum leptin levels or salivary cortisol.

Conclusions: In female athletes nutritional composition has an impact on serum hormones (leptin, IGF-1 as well as estradiol) and may be also on cytokines (IL-6). Leptin, IGF-1 and salivary cortisol levels represent the intensity of physical training and possibly overtraining. In our female athletes no findings indicative of female athlete triad could be demonstrated.