The Relationship between resistance exercise induced testosterone and cortisol responses and steroid receptor phosphorylation
The precise contribution of hormones to resistance training adaptations remains unclear. Recently, resistance exercise (RE) has been shown to change phosphorylation of androgen (pAR) & glucocorticoid receptors (pGR). Examining the relationships between the hormonal responses & steroid receptor phosphorylation may elucidate the role of acute hormonal responses to training adaptations. PURPOSE: The purpose of this study was to examine relationships between exercise-induced hormonal responses and pGR & pAR. METHODS: Resistance trained (RT) (n = 10; age = 21.3±1.7yrs, ht = 175.8±6.8cm, bodymass = 84.5±13.5kg) & untrained (UT) (n = 9; age = 20.8±3.1yrs, ht = 178.7±8.9cm, bodymass = 81.0±14.0kg) men completed an acute RE session of 6 sets of 10 reps, & 4 sets of 10 reps at 75% 1RM of barbell back squats, & knee extension, respectively. Muscle biopsies were obtained at rest, 10+, 30+, 60+, & 180+ minutes post-exercise & analyzed for total AR, pAR at ser81, ser213, ser515, ser650, total GR, and pGR at ser134, ser211, ser226. Testosterone & cortisol samples were obtained before, & up to 45 minutes post-exercise. Pearson correlations were performed to determine relationships between endocrine responses (area-under-curve [AUC]) & changes in total & phosphorylated AR & GR. Significance was determined at p≤0.05. RESULTS: The change in total AR at 180+ was correlated with cortisol (Pooled: r = -0.668, p = 0.002) & was strongest in RT subjects (RT: r = -0.767, p = 0.010). Cortisol was correlated with pARser81 at 60+ (r = 0.601, p = 0.006) & 180+ (r = 0.537, p = 0.018). Cortisol was correlated with the change in pARser650 at 180+ (r = 0.724, p = 0.018) in RT subjects. In UT the changes in pGRser134 & pGRser226 were correlated at 10+ (r = 0.987, p = 0.001) & 30+ (r = 0.943, p = 0.001). CONCLUSION: Cortisol responses were related to AR content, & changes in phosphorylation at sites regulating AR ligand sensitivity, & AR localization. There was a training status-specific relationship in UT subjects between pGR sites that regulate receptor localization, & GR sensitivity to cellular stress. Individualized cortisol responses are strongly related to AR activity and may explain the discrepancy in studies that solely investigated anabolic hormones & training adaptations, since these relationships also appear to be specific to different training statuses.
Golbarg, Borna; Nicoll, Justin X.; Sontag, Stephanie A.; Mosier, Eric M.; and Fry, Andrew C.
"The Relationship between resistance exercise induced testosterone and cortisol responses and steroid receptor phosphorylation,"
International Journal of Exercise Science: Conference Proceedings: Vol. 14:
2, Article 125.
Available at: https://digitalcommons.wku.edu/ijesab/vol14/iss2/125
Health and Physical Education Commons, Medical Education Commons, Sports Sciences Commons