Skeletal Muscle Gene Expression After A Follicular Based And A Luteal Based Training In A Female Athlete

Abstract

PURPOSE: Each phase of the menstrual cycle is characterized by a certain profile of different hormones. Menstrual cycle specific regulation of many hormones is not clear so far. This is especially true for the interaction between estradiol, human growth hormone (hGH), and IGF-1, all of them possible anabolic hormones on the level of the muscular cell and therefore important supporting factors during strength training. We, therefore, decided to conduct a pilot study in order to investigate possible different effects of follicular phase-based (FT) versus luteal phase-based (LT) strength training on the gene expression profile of skeletal muscle. METHODS: One healthy eumenorrheic woman completed a strength training program for 3 menstrual cycles (approx. 12 weeks). The subject performed FT with muscle groups of the right side of the body and LT with muscle groups of the left side of the body. FT was organized 4 times a week in the follicular phase and once a week in the luteal phase, and LT was organized 4 times a week in the luteal phase and once a week in the follicular phase. Gene expression profile was determined in skeletal muscle biopsy samples (m. vastus lateralis, both legs prior to and after 3 months of either FT or LT, respectively) via microarray encompassing 1.14 million exon probes (Exon Chip) and subsequent Gene Ontology Analysis. RESULTS: Microarray analysis revealed an increase (at least 1.5 fold) in 414 genes and a decrease in 87 genes after FT. LT only induced an increase in 82 genes and a decrease in 75 genes. Most up-regulated genes belonged to processes like cellular metabolism, oxidoreductase activities, generation of precursor metabolites and energy, electron transport, translation, cellular biosynthetic processes, transmembrane receptor activities, electron carrier activity, NADH dehydrogenase (ubiquinone) activity, and mitochondrial electron transport. CONCLUSIONS: The much higher number of activated genes after FT is in accordance with recently published findings of higher maximal strength gains and gains in muscle mass after FT as compared to LT. This is probably due to the specific hormonal milieu during each phase of the cycle. More subjects have to be included in order to further analyze menstrual cycle specific training effects.