Complex Network Model Reveals the Impact of Inspiratory Muscle Pre-Activation on Interactions among Physiological Responses and Muscle Oxygenation during Running and Passive Recovery

Figures

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  Figure 1. Panel A.Experimental design. First and second visits were conducted for sample characterization and familiarization. Additionally, the maximal inspiratory pressure (MIP) and global strength index of inspiratory muscles (SI) were measured. Exercise (all-out in tethered running, AO30) and recovery (both, without or with inspiratory muscle pre-activation (IMPA)) were conducted at the third and fourth randomized visits, separated by 48–72 h. Panel B. Scenarios for constructing the complex networks and complex network nodes used in these four scenarios. Legend: AO30 = all-out 30 s, IMPA = inspiratory muscle pre-activation, BM = body mass, %BF = percentage of body fat, MIP = maximal inspiratory pressure, SI = global strength index of inspiratory muscles, Lac = blood lactate, HR = heart rate, SpO2 = arterial oxygen saturation, RPE = perceived exertion, D = delta between final and initial results, BB = biceps brachii, VL = vastus lateralis, O2Hb = oxyhemoglobin relative concentration, HHb = deoxyhemoglobin relative concentration, tHb = total hemoglobin, TSI = tissue saturation index.

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  Figure 2. Graphs and top five node results obtained by complex network analysis using the Degree metric in two exercise scenarios: without inspiratory muscle pre-activation (Scenario AO30 shown in Panel A) and with inspiratory muscle pre-activation (Scenario IMPA + AO30, Panel B). Graph visualizations were done using Gephi software (version 0.9.2, Paris, France). Legend: AO30 = all-out 30 s, IMPA = inspiratory muscle pre-activation, Hgt = height, BM = body mass, %BF = percentage of body fat, MIP = maximal inspiratory pressure, SI = global strength index of inspiratory muscles, Lac = blood lactate, HR = heart rate, SpO2 = arterial oxygen saturation, RPE = perceived exertion, O2Hb = oxyhemoglobin relative concentration, HHb = deoxyhemoglobin relative concentration, tHb = total hemoglobin, TSI = tissue saturation index. Abbreviations accompanied by p, m, min and D represent peak, mean, minimum and delta (between final and initial results), respectively. Abbreviations accompanied by BB and VL represent the results in the biceps brachii and vastus lateralis, respectively.

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  Figure 3. Graphs and top five node results obtained by complex network analysis using Betweenness Centrality (Panels A,B) and Eigenvector Centrality metrics (Panels C,D) in two exercise scenarios: without inspiratory muscle pre-activation (Scenario AO30, Panels A,C) and with inspiratory muscle pre-activation (Scenario IMPA + AO30, Panels B,D). Graph visualizations were done using Gephi software (version 0.9.2, Paris, France). Legend: AO30 = all-out 30 s, IMPA = inspiratory muscle pre-activation, Hgt = height, BM = body mass, %BF = percentage of body fat, MIP = maximal inspiratory pressure, SI = global strength index of inspiratory muscles, Lac = blood lactate, HR = heart rate, SpO2 = arterial oxygen saturation, RPE = perceived exertion, O2Hb = oxyhemoglobin relative concentration, HHb = deoxyhemoglobin relative concentration, tHb = total hemoglobin, TSI = tissue saturation index. Abbreviations accompanied by p, m, min and D represent peak, mean, minimum and delta (between the final and initial results), respectively. Abbreviations accompanied by BB and VL represent the results in the biceps brachii and vastus lateralis, respectively.

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  Figure 4. Graphs and top five node results obtained by complex network analysis using the Pagerank metric in exercise scenarios without inspiratory muscle pre-activation (Scenario AO30, at Panel A) and with inspiratory muscle pre-activation (Scenario IMPA + AO30, at Panel B). Graph visualizations were done using Gephi software (version 0.9.2, Paris, France). Legend: AO30 = all-out 30 s, IMPA = inspiratory muscle pre-activation, Hgt = height, BM = body mass, %BF = percentual of body fat, MIP = maximal inspiratory pressure, SI = global strength index of inspiratory muscles, Lac = blood lactate, HR = heart rate, SpO2 = arterial oxygen saturation, RPE = perceived exertion, O2Hb = oxyhemoglobin relative concentration, HHb = deoxyhemoglobin relative concentration, tHb = total hemoglobin, TSI = tissue saturation index. Abbreviations accompanied by p, m, min and D represent peak, mean, minimum and delta (between the final and initial results), respectively. Abbreviations accompanied by BB and VL represent the results in the biceps brachii and vastus lateralis, respectively.

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  Figure 5. Graphs and top five node results obtained by complex network analysis using the Degree metric in two recovery scenarios: without inspiratory muscle pre-activation (Scenario Recovery, at Panel A) and with inspiratory muscle pre-activation (Scenario IMPA + Recovery, at Panel B). Graph visualizations were done using Gephi software (version 0.9.2, Paris, France). Legend: AO30 = all-out 30 s, IMPA = inspiratory muscle pre-activation, Hgt = height, BM = body mass, %BF = percent body fat, MIP = maximal inspiratory pressure, SI = global strength index of inspiratory muscles, Lac = blood lactate, HR = heart rate, SpO2 = arterial oxygen saturation, O2Hb = oxyhemoglobin relative concentration, HHb = deoxyhemoglobin relative concentration, tHb = total hemoglobin, TSI = tissue saturation index. Abbreviations accompanied by p, m and min represent peak, mean and minimum values, respectively. Abbreviations accompanied by BB and VL represent the results in the biceps brachii and vastus lateralis, respectively.

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  Figure 6. Graphs and top five node results obtained by complex network analysis using Betweenness Centrality (Panels A,B) and Eigenvector Centrality (Panels C,D) metrics in two recovery scenarios: without inspiratory muscle pre-activation (Scenario Recovery, at Panel A,C) and with inspiratory muscle pre-activation (Scenario IMPA + Recovery, at Panels B,D). Graph visualizations were done using Gephi software (version 0.9.2, Paris, France). Legend: AO30 = all-out 30 s, IMPA = inspiratory muscle pre-activation, Hgt = height, BM = body mass, %BF = percentage of body fat, MIP = maximal inspiratory pressure, SI = global strength index of inspiratory muscles, Lac = blood lactate, HR = heart rate, SpO2 = arterial oxygen saturation, O2Hb = oxyhemoglobin relative concentration, HHb = deoxyhemoglobin relative concentration, tHb = total hemoglobin, TSI = tissue saturation index. Abbreviations accompanied by p, m and min represent peak, mean and minimum values, respectively. Abbreviations accompanied by BB and VL represent the results in the biceps brachii and vastus lateralis, respectively.

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  Figure 7. Graphs and top five node results obtained by complex network analysis using the Pagerank metric in two recovery scenarios: without inspiratory muscle pre-activation (Scenario Recovery, at Panel A) and with inspiratory muscle pre-activation (Scenario IMPA + Recovery, at Panel B). Graph visualizations were done using Gephi software (version 0.9.2, Paris, France). Legend: AO30 = all-out 30 s, IMPA = inspiratory muscle pre-activation, Hgt = height, BM = body mass, %BF = percentage of body fat, MIP = maximal inspiratory pressure, SI = global strength index of inspiratory muscles, Lac = blood lactate, HR = heart rate, SpO2 = arterial oxygen saturation, O2Hb = oxyhemoglobin relative concentration, HHb = deoxyhemoglobin relative concentration, tHb = total hemoglobin, TSI = tissue saturation index. Abbreviations accompanied by p, m and min represent peak, mean and minimum values, respectively. Abbreviations accompanied by BB and VL represent the results in the biceps brachii and vastus lateralis, respectively.