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.