The Effect of Menstrual Cycle Phase on IGF-1 and Myostatin after an Acute Bout of Anaerobic Exercise: A Preliminary Analysis

Authors

Kelsi R. Lambright, Texas Woman's UniversityFollow
Cayla Clark, Texas Woman's UniversityFollow
Ashley Latchford, Texas Woman's UniversityFollow
Edwin J. Davila, Precision Health, San Antonio, TXFollow
Dan E. Newmire, Texas Woman's UniversityFollow

Abstract

Hormonal fluctuations throughout the menstrual cycle influence various physiological processes, including skeletal muscle metabolism. Understanding how anabolic and catabolic pathways respond to anaerobic exercise in females is crucial for uncovering the mechanisms behind muscle adaptations. The limited research on the influence of menstrual cycle fluctuations on muscle metabolism underscores the need for this study and further exploration of exercise physiology in females. PURPOSE: The purpose of this study is to investigate the effects of menstrual cycle phases on the anabolic hormone-insulin-like growth factor-1 (IGF-1) and the catabolic regulator myostatin (GDF-8) in response to a bout of anaerobic exercise in eumenorrheic women. It was hypothesized that IGF-1 levels will increase and myostatin levels will decrease following anaerobic exercise, with variations in these responses influenced by different phases of the menstrual cycle. METHODS: This study utilized a repeated measure ANOVA within-subjects design involving eumenorrheic women (n=4) age 21.5±3.3 years, height of 157.9±7.6 cm, weight 70.7±28.7 kg, BMI 24.1±2.9 kg/m², and body fat percentage of 34.6±7.1%. The participants tracked their menstrual cycles for two months prior to the exercise sessions to confirm cycle phases using calendar counting and ovulation test strips. Participants completed a Wingate test during three menstrual cycle phases including early follicular (EF), late follicular (LF), and mid-luteal (ML) with pre- and post-exercise blood samples collected to measure serum IGF-1 and myostatin levels. Each session included a 30-sec Wingate test (7.5% resistance), with blood samples taken pre-exercise, 10 min post-exercise, and 60 min post-exercise to assess hormonal responses. RESULTS: In IGF-1 serum concentrations, no significant effect was found during the EF phase (p > .05, η²=.355), LF phase (p > .05, η²=.028), or ML phase (p > .05, η²=.022). There were also no significant effects found in pretest (p > .05, η²= .204), 10 min posttest (p > .05, η²= .259), or 60 min posttest (p > .05, η²= .274). Myostatin serum concentrations had no significant effects during the EF phase (p > .05, η²= .424), LF phase (p > .05, η²= .610), or ML phase (p > .05, η²= .052). No significant effect was found for the myostatin pretest (p > .05, η²= .108), 10 min posttest (p > .05, η²= .115), or 60 min posttest (p > .05, η²= .288). CONCLUSION: Although further investigation with a larger sample size is warranted, results of this study indicate that there are no changes in IGF-1 and myostatin serum concentrations between menstrual cycle phases or time points post-Wingate test.

Recommended Citation

Lambright, Kelsi R.; Clark, Cayla; Latchford, Ashley; Davila, Edwin J.; and Newmire, Dan E. (2025) "The Effect of Menstrual Cycle Phase on IGF-1 and Myostatin after an Acute Bout of Anaerobic Exercise: A Preliminary Analysis," International Journal of Exercise Science: Conference Proceedings: Vol. 2: Iss. 17, Article 18.
Available at: https://digitalcommons.wku.edu/ijesab/vol2/iss17/18