Abstract
Circulating estradiol is known to influence multiple target tissues; however, its role in neuromuscular function and adipose-related systemic inflammation remains poorly understood. PURPOSE: To examine estradiol as a predictor of body composition, neuromuscular activation, and markers of inflammation in untrained pre- and post-menopausal women. METHODS: This secondary analysis used a cross-sectional design including eleven untrained women (pre-menopausal, n=6; age=23.3±4.3 years; height=160.6±8.3 cm; weight=60.5±11.6 kg; post-menopausal, n=5; age=61.0±3.3 years; height=164.2±8.0 cm; weight=77.1±9.3 kg). All participants underwent DXA scans to determine total fat mass (TFM), visceral fat mass (VFM), and fat-free mass (FFM). Lower body muscle quality was calculated as relative strength divided by DXA-derived FFM. One-repetition maximum (1RM) strength was assessed using NSCA guidelines on a standard leg press machine. Surface electromyography (EMG) was collected from the vastus lateralis (VL) and rectus femoris (RF) using standardized skin preparation and electrode placement, and signals were analyzed using EMGRMS for peak activation. Linear regressions were performed to examine associations between estradiol, body composition, neuromuscular activation, and tumor necrosis factor-alpha (TNF-α). RESULTS: Estradiol concentrations were not significantly associated with DXA-derived FFM or lower body muscle quality (p>0.10). Estradiol was significantly inversely associated with TFM (R²=0.51, p=0.014) and demonstrated an even stronger inverse association with VFM (R²=0.81, p=0.00015). TFM and VFM were positively associated with TNF-α, accounting for (R2=0.33, p=0.064, R2=0.67 p=0.002), respectively. In contrast, estradiol was positively associated with VL EMGRMS (R2=0.48, p=0.018) and RF EMGRMS (R2=0.59, p=0.006) during 1RM leg press. CONCLUSION: Circulating estradiol appears to be more strongly related to VFM and muscular activation than FFM or MQ in untrained women. These findings support a potential that estrogen withdrawal may contribute to both increased visceral adiposity-and systemic inflammation as well as reduced neuromuscular activation across the female lifespan.
Recommended Citation
Artrip, Macy J.; Chapman-Lopez, Tomas; Luera, Micheal; Kelly, Jaci; Florez, Christine M.; Taylor, Lem; Willoughby, Darryn; and Parra, Mandy E.
(2026)
"Associations Between Circulating Estradiol, Adiposity and Neuromuscular Activation in Untrained Women,"
International Journal of Exercise Science: Conference Proceedings: Vol. 2:
Iss.
18, Article 146.
Available at:
https://digitalcommons.wku.edu/ijesab/vol2/iss18/146