Fig 1.
Dynamics of the HPA and SA axes.
Process of cortisol production and secretion via the HPA axis (left) and catecholamine production and secretion via the SA axis (right).
Table 1.
Parameters used in S(t).
Table 2.
Parameter ranges for Morris screening.
Fig 2.
Stress S(t) experienced by subjects over the course of the experimental protocol described in Section 2.2.
Fig 3.
Time series data for each subject’s cortisol concentrations measured by Webb et al. Each colored curve corresponds to an individual subject. Circles indicate measured values; shaded area indicates the duration of the exercise protocol. Subjects A-E are the five representative subjects included in Section 3.2.
Fig 4.
A: Morris index (MI) for each of the 19 parameters. Blue line indicates the mean MI. B: Variance () vs. Mean (
) for each of the 19 parameters.
Fig 5.
Cortisol, epinephrine, and norepinephrine concentrations for 6 subjects after optimization of sensitive parameter set. The blue circles are the measured values from Webb et al. [13] and the red curve is the model solution with optimized parameters. The shaded region denotes the duration of the stress stimulus.
Table 3.
Optimized values for influential parameters.
Table 4.
Error measures.