Physiological behavior during stress anticipation across different chronic stress exposure adaptive models.

Anticipation of stress induces physiological, behavioral and cognitive adjustments that are required for an appropriate response to the upcoming situation. Additional research examining the response of cardiopulmonary parameters and stress hormones during anticipation of stress in different chronic stress adaptive models is needed. As an addition to our previous research, a total of 57 subjects (16 elite male wrestlers, 21 water polo player and 20 sedentary subjects matched for age) were analyzed. Cardiopulmonary exercise testing (CPET) on a treadmill was used as the laboratory stress model; peak oxygen consumption (VO2) was obtained during CPET. Plasma levels of adrenocorticotropic hormone (ACTH), cortisol, alpha-melanocyte stimulating hormone (alpha-MSH) and N-terminal-pro-B type natriuretic peptide (NT-pro-BNP) were measured by radioimmunometric, radioimmunoassay and immunoassay sandwich technique, respectively, together with cardiopulmonary measurements, 10 minutes pre-CPET and at the initiation of CPET. The response of diastolic blood pressure and heart rate was different between groups during stress anticipation (p = 0.019, 0.049, respectively), while systolic blood pressure, peak VO2 and carbon-dioxide production responses were similar. ACTH and cortisol increased during the experimental condition, NT-pro-BNP decreased and alpha-MSH remained unchanged. All groups had similar hormonal responses during stress anticipation with the exception of the ACTH/cortisol ratio. In all three groups, ΔNT-pro-BNP during stress anticipation was the best independent predictor of peak VO2 (B = 36.01, r = 0.37, p = 0.001). In conclusion, the type of chronic stress exposure influences the hemodynamic response during anticipation of physical stress and the path of hormonal stress axis activation. Stress hormones released during stress anticipation may hold predictive value for overall cardiopulmonary performance during the stress condition.

LAY SUMMARYThe study revealed differences in hormonal and hemodynamic responses during anticipation of stress between athletes and sedentary participants. Stress hormones released during stress anticipation may hold predictive value for overall cardiopulmonary performance during the stress condition.

The alpha-melanocyte stimulating hormone is related to heart rate during exercise recovery.

Alpha-melanocyte-stimulating hormone (alpha-MSH) is a part of the hormonal stress system with proven cardiovascular effects. Heart rate recovery (HRR) following exercise is strongly correlated to overall fitness and future adverse cardiovascular events. The current study examined the predictive value of alpha-MSH for HRR following exercise testing.Cardiopulmonary exercise testing (CPET) on a treadmill was used to measure HR and oxygen consumption (V̇O2) in 16 elite male wrestlers (W), 21 water polo player (WP) and 20 sedentary subjects (C) matched for age. Plasma levels of alpha-MSH were measured by radioimmunoassay technique in four phases of CPET: 1) 10 min pre-CPET at rest; 2) at the initation of CPET; 3) at peak CPET; and 4) at the third minute of recovery. The WP group had significantly higher HRR compared to than W and C groups, who did not have significantly different values. Significant difference in alpha-MSH measurements and patterns during CPET between groups was not observed (p > 0.05). When combining all three groups, we observed a significant correlation between V̇O2 recovery and alpha-MSH recovery/peak (r = -0.3, p = 0.022). HRR and ΔHRR/peak significantly correlated with alpha-MSH at all four measurment points (r = -0.4; p < 0.01 for all). On multiple regression analysis, which included anthropometric and hormonal measures, the best independent predictor of HRR and ΔHRR/peak was alpha-MSH during recovery (B = -1.0, -0.5; SE = 0.3, 0.1; CI = -1.5 to -0.4, -0.7 to -0.2; p = 0.001 respectively). In conclusion, alpha-MSH measured during exercise recovery holds predictive value for HRR and ΔHRR/peak, suggesting a contributing role to integrative regulation of overall cardiopulmonary performance. CONDENSED ABSTRACT: Present study examined the predictive value of alpha-melanocyte stimulating hormone (alpha-MSH) for heart rate recovery (HRR) in elite male wrestlers, water polo players and sedentary subjects matched for age. Alpha-MSH measured during exercise recovery holds predictive value for HRR and ΔHRR/peak, suggesting a contributing role to integrative regulation of overall cardiopulmonary performance.