Values of <i>IL6</i>_<i>b</i>, <i>T</i>_<i>v</i> and exercise duration.

<p>Values of <i>IL6</i>_<i>b</i>, <i>T</i>_<i>v</i> and exercise duration.</p

IL-6 weighted residuals.

<p>IL-6 weighted residuals.</p

Model validation results obtained using the conditions reported in the study by Febbraio et al.

<p>(A) <i>PVO</i>_<i>2max</i> model prediction (B) Measured IL-6 concentrations (means ± SEM) from Febbraio et al. [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0181224#pone.0181224.ref025" target="_blank">25</a>], shown together with the model prediction (solid line).</p

Model validation results obtained using the conditions reported in the study by Steensberg et al.

<p>(A) <i>PVO</i>_<i>2max</i> model prediction (B) Measured IL-6 concentrations (medians and quartiles) from Steensberg et al. [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0181224#pone.0181224.ref008" target="_blank">8</a>], shown together with the model prediction (solid line).</p

Two-compartment description of the IL-6 dynamics during exercise.

<p>Skeletal muscle secretes IL-6 in the local (muscle) blood flow (<i>IL6</i>_<i>m</i><i>(t)</i>) in response to change in oxygen consumption (<i>PVO</i>_<i>2max</i>) with a secretion rate equal to <i>SR</i>_<i>e</i>x. Plasma IL-6 (<i>IL6</i>_<i>p</i><i>(t)</i>) is the result of adipose tissue secretion (<i>Ra</i>_<i>IL6</i>), hepatosplanchnic viscera removal (<i>k</i>_<i>e</i>) and contribution coming from muscle compartment (through <i>k</i>_<i>m</i>).</p

Model validation results obtained using the conditions reported in the study by Fischer et al.

<p>(A) <i>PVO</i>_<i>2max</i> model prediction (B) Measured IL-6 concentrations (means ± SEM) from Fischer et al. [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0181224#pone.0181224.ref030" target="_blank">30</a>], shown along with the model prediction (solid line).</p

Model fit results.

<p>(A) <i>PVO</i>_<i>2max</i> model prediction (B) Mean model fit (solid line) for IL-6. Measured IL-6 concentrations (means ± SEM) from Ostrowski et al. [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0181224#pone.0181224.ref029" target="_blank">29</a>] are shown, along with the model fit.</p

Reactions in liver.

<p>Simulations of net hepatic glycogen breakdown (solid line) and net hepatic gluconeogenesis (dotted line) in response to the exercise performed in the study 3. The gray zone refers to the exercise period.</p

Personalizing physical exercise in a computational model of fuel homeostasis

<div><p>The beneficial effects of physical activity for the prevention and management of several chronic diseases are widely recognized. Mathematical modeling of the effects of physical exercise in body metabolism and in particular its influence on the control of glucose homeostasis is of primary importance in the development of eHealth monitoring devices for a personalized medicine. Nonetheless, to date only a few mathematical models have been aiming at this specific purpose. We have developed a whole-body computational model of the effects on metabolic homeostasis of a bout of physical exercise. Built upon an existing model, it allows to detail better both subjects’ characteristics and physical exercise, thus determining to a greater extent the dynamics of the hormones and the metabolites considered.</p></div

Dynamics of suprabasal plasma lactate concentration in response to exercise.

<p>Model fit (colored areas) vs experimental data (circles) expressed as mean ± SE. The colored areas show the range of the dynamic responses of the model to the variability of the subjects’ characteristics as reported in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1006073#pcbi.1006073.t002" target="_blank">Table 2</a> (blue: females; red: males); individual response curves related to each simulation are available. The gray zone refers to the exercise period. The dark gray zone refers to the exercise performed above the LT until minute 32. The colored area shows the dynamic responses of the model to the variability of the subjects’ characteristics as reported in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1006073#pcbi.1006073.t002" target="_blank">Table 2</a>. A: Trained individuals from the study 1. B: Untrained individuals from the study 1. C: Trained individuals from the study 4. D: Untrained individuals from the study 4. E: Individuals from the study 5.</p